{ "url": "https://scratch.mit.edu", "auditedAt": "2026-07-24T00:33:57.126Z", "mode": "report", "status": "completed", "statusDetail": "Coverage-complete representative audit of seven public/guest paths. Authenticated account, moderation, studio-detail, profile, payment/donation completion, and project-save/share states were not covered because they require credentials, user mutation, or duplicate inspected templates.", "page": { "appType": "hybrid", "framework": "React-based SPA/hybrid surfaces plus Scratch editor VM/canvas", "notes": "Public content is client-rendered into #app. Homepage/listing/project/editor/join templates were sampled." }, "evidenceUsed": [ "screenshot", "video", "dom", "evaluate-probe", "layout-metrics", "trace", "har", "discoverability", "headers", "cookies", "trackers", "secrets", "images", "lighthouse", "heap-summary", "curl robots/sitemap" ], "guidanceConsulted": [ "accessibility", "accessible-error-announcement", "language-detection", "language-model", "summarizer", "translator", "css", "highlight-text-ranges", "css-layout", "animated-select-picker", "autofill-address-form", "autofill-highlight-inputs", "autofill-payment-form", "autofill-sign-in-form", "autofill-sign-up-form", "brand-consistent-forms", "branded-select-styling", "custom-select-picker-layouts", "form-fields-automatically-fit-contents", "forms", "required-field-feedback", "rich-media-picker", "select-menu-interaction", "validate-input-after-interaction", "html", "passkey-authentication", "passkey-conditional-create", "passkey-management", "passkey-reauthentication", "passkey-registration", "passkeys", "batch-analytics-events", "break-up-long-tasks", "calculate-total-foreground-time", "conditional-async-dependencies", "defer-rendering-heavy-content", "defer-work-until-scroll-ends", "deprioritize-background-fetches", "detect-initial-visibility-state", "efficient-background-processing", "faster-spa-view-transitions", "full-session-analytics", "identify-heavy-scripts", "identify-inp-causes", "improve-next-page-load-performance", "interactions-in-complex-layouts", "optimize-image-priority", "optimize-preload-priority", "optimize-script-priority", "performance", "resolution-optimized-pseudo-elements", "schedule-tasks-by-priority", "sequence-distributed-events", "privacy", "security", "adapt-scrollbar-to-contrast-preferences", "anchor-positioning-tab-underline", "animate-element-entry-exit", "animate-to-from-top-layer", "animate-to-intrinsic-sizes", "apply-webgl-shaders", "calculate-event-differentials", "calculate-with-intrinsic-sizes", "capture-location-agnostic-data", "carousel-slide-effects", "carousel-snap-highlights", "child-state-based-styling", "complex-shapes", "component-specific-light-dark-theme", "consistent-cross-document-transitions", "content-based-styling", "coordinate-global-events", "cross-document-transitions", "customize-scrollbar-color-and-thickness", "dark-mode", "declarative-button-actions", "declarative-dialog-popover-control", "deliver-optimized-decorative-images", "design-token-reactivity", "directional-navigation-transitions", "dynamic-sibling-animations", "dynamic-sibling-styling", "export-html-media-from-canvas", "expose-canvas-content-to-browser-features", "flicker-free-client-side-ab-testing", "fluid-scaling", "format-human-readable-durations", "group-element-transitions", "improve-text-layout-and-legibility", "individual-transform-properties", "interactive-content-in-3d-scenes", "interactive-content-reveal", "interest-triggered-action-previews", "interest-triggered-tooltips", "light-dismiss-a-dialog", "manage-recurring-intervals", "model-partial-time-concepts", "move-dom-element-without-losing-state", "navigation-drawer", "overflow-clipping-control", "parallax-scroll-effects", "persistent-app-tours", "persistent-toast-notifications", "persistent-top-layer-ui", "physics-based-easing", "platform-controls-dismiss-dialog", "position-aware-tooltips", "precise-text-alignment", "prevent-text-wrapping", "pull-to-reveal", "reduce-style-repetition", "resilient-context-menus-and-nested-dropdowns", "same-document-transitions", "scroll-entry-exit-effects", "scroll-position-aware-elements", "scroll-progress-indicator", "scroll-snap-realtime-feedback", "scroll-snap-state-sync", "scroll-target-on-load", "scrollability-affordance-hints", "scrollytelling", "search-hidden-content", "shaped-cutouts", "shrinking-header-on-scroll", "size-aware-styling", "soft-edge-content-fade", "stabilize-reactive-state", "stack-drill-down", "style-parent-with-has", "support-global-calendar-systems", "swipe-to-remove", "visually-stable-font-fallbacks", "visually-stable-mixed-fonts", "visually-texture-content", "agentic-forms", "agentic-javascript-tools", "webmcp" ], "artifacts": [ { "type": "screenshot", "path": "evidence/home-dark.png", "caption": "home dark", "findingIds": [ "F01" ] }, { "type": "other", "path": "evidence/preferences-ui-probe.json", "caption": "preferences ui probe", "findingIds": [ "F01" ] }, { "type": "video", "path": "evidence/reduced-motion-carousel.mp4", "caption": "reduced motion carousel", "findingIds": [] }, { "type": "lighthouse", "path": "evidence/lighthouse-home-summary.json", "caption": "lighthouse home summary", "findingIds": [ "F02", "F09", "F10", "F13", "F14", "F15", "F16", "F17", "F18", "F20" ] }, { "type": "other", "path": "evidence/images.json", "caption": "images", "findingIds": [ "F02", "F09", "F14", "F15", "F16", "F19", "F32" ] }, { "type": "other", "path": "evidence/editor-accessibility-probe.json", "caption": "editor accessibility probe", "findingIds": [ "F02", "F09", "F14", "F15", "F16" ] }, { "type": "video", "path": "evidence/home-to-explore.mp4", "caption": "home to explore", "findingIds": [ "F03" ] }, { "type": "other", "path": "evidence/platform-probe.json", "caption": "platform probe", "findingIds": [ "F04", "F05", "F08", "F18", "F20", "F22", "F23", "F29", "F30" ] }, { "type": "dom", "path": "evidence/home-dom.json", "caption": "home dom", "findingIds": [ "F04", "F05", "F08", "F18", "F20", "F22", "F23", "F29", "F30" ] }, { "type": "screenshot", "path": "evidence/home-desktop.png", "caption": "home desktop", "findingIds": [] }, { "type": "screenshot", "path": "evidence/project.png", "caption": "project", "findingIds": [] }, { "type": "screenshot", "path": "evidence/editor.png", "caption": "editor", "findingIds": [ "F07", "F11", "F17" ] }, { "type": "screenshot", "path": "evidence/home-mobile.png", "caption": "home mobile", "findingIds": [] }, { "type": "layout", "path": "evidence/home-mobile-layout.json", "caption": "home mobile layout", "findingIds": [ "F10" ] }, { "type": "screenshot", "path": "evidence/join.png", "caption": "join", "findingIds": [ "F06", "F26", "F31" ] }, { "type": "other", "path": "evidence/join-page-probe.json", "caption": "join page probe", "findingIds": [ "F06", "F26", "F31" ] }, { "type": "other", "path": "evidence/join-validation-probe.json", "caption": "join validation probe", "findingIds": [ "F06", "F26", "F31" ] }, { "type": "screenshot", "path": "evidence/ideas.png", "caption": "ideas", "findingIds": [] }, { "type": "screenshot", "path": "evidence/project-mobile.png", "caption": "project mobile", "findingIds": [ "F07", "F17" ] }, { "type": "layout", "path": "evidence/project-mobile-layout.json", "caption": "project mobile layout", "findingIds": [ "F07", "F17" ] }, { "type": "layout", "path": "evidence/editor-mobile-layout.json", "caption": "editor mobile layout", "findingIds": [ "F07", "F11", "F17" ] }, { "type": "screenshot", "path": "evidence/404.png", "caption": "404", "findingIds": [] }, { "type": "trace-summary", "path": "evidence/home-trace-summary.json", "caption": "home trace summary", "findingIds": [ "F10" ] }, { "type": "other", "path": "evidence/home-summary.json", "caption": "home summary", "findingIds": [ "F12", "F13", "F19", "F25", "F32", "F33", "F34" ] }, { "type": "har", "path": "evidence/home.har", "caption": "home", "findingIds": [ "F12", "F13", "F25", "F33", "F34" ] }, { "type": "other", "path": "evidence/recon.json", "caption": "recon", "findingIds": [] }, { "type": "other", "path": "evidence/explore-probe.json", "caption": "explore probe", "findingIds": [] }, { "type": "other", "path": "evidence/project-probe.json", "caption": "project probe", "findingIds": [] }, { "type": "discoverability", "path": "evidence/discoverability-home.json", "caption": "discoverability home", "findingIds": [ "F21", "F28" ] }, { "type": "screenshot", "path": "evidence/discoverability-home-rendered.png", "caption": "discoverability home rendered", "findingIds": [ "F21", "F28" ] }, { "type": "screenshot", "path": "evidence/discoverability-home-crawler.png", "caption": "discoverability home crawler", "findingIds": [ "F21", "F28" ] }, { "type": "discoverability", "path": "evidence/discoverability-project.json", "caption": "discoverability project", "findingIds": [ "F21", "F28" ] }, { "type": "screenshot", "path": "evidence/discoverability-project-rendered.png", "caption": "discoverability project rendered", "findingIds": [ "F21", "F28" ] }, { "type": "screenshot", "path": "evidence/discoverability-project-crawler.png", "caption": "discoverability project crawler", "findingIds": [ "F21", "F28" ] }, { "type": "other", "path": "evidence/robots.txt", "caption": "robots", "findingIds": [] }, { "type": "other", "path": "evidence/sitemap.xml", "caption": "sitemap", "findingIds": [] }, { "type": "other", "path": "evidence/headers.json", "caption": "headers", "findingIds": [ "F24", "F25", "F27" ] }, { "type": "other", "path": "evidence/cookies.json", "caption": "cookies", "findingIds": [ "F24", "F25", "F27" ] }, { "type": "other", "path": "evidence/trackers.json", "caption": "trackers", "findingIds": [ "F24", "F25", "F27" ] }, { "type": "other", "path": "evidence/secrets.json", "caption": "secrets", "findingIds": [ "F24", "F25", "F27" ] }, { "type": "screenshot", "path": "evidence/explore.png", "caption": "explore", "findingIds": [] }, { "type": "heap", "path": "evidence/editor-heap-baseline.heapsnapshot", "caption": "editor heap baseline", "findingIds": [] }, { "type": "heap", "path": "evidence/editor-heap-post.heapsnapshot", "caption": "editor heap post", "findingIds": [] } ], "config": { "loaded": false }, "coverage": { "catalogVersion": "modern-web-guidance@0.0.172", "catalogChecksum": "sha256:78ccfdb2d483f4c57d9dafed80fd86c6265585a56457c8dcfddc254b80fb44d7", "expected": 58, "recorded": 58, "judged": 58, "blocked": 0, "notRun": 0, "missing": 0, "unknown": 0, "duplicates": 0, "complete": true }, "checkOutcomes": [ { "principleId": "respect-user-preferences", "checkId": "respects-color-scheme", "status": "issues", "confidence": "high", "method": "Dark emulation + computed style", "evidence": "The dark-condition screenshot is visually identical to the default; the computed probe reports colorScheme \"normal\" under a matching dark query.", "pathIds": [ "home" ], "artifacts": [ "evidence/home-dark.png", "evidence/preferences-ui-probe.json" ], "findingIds": [ "F01" ] }, { "principleId": "respect-user-preferences", "checkId": "respects-reduced-motion", "status": "pass", "confidence": "high", "method": "Active evidence review for respects-reduced-motion", "evidence": "Reduced-motion carousel recording produced one static frame over 3 seconds and the animation probe reported no running animations.", "artifacts": [ "evidence/reduced-motion-carousel.mp4" ], "pathIds": [ "home" ] }, { "principleId": "respect-user-preferences", "checkId": "respects-contrast", "status": "issues", "confidence": "high", "method": "Lighthouse contrast + CSS preference inspection", "evidence": "Lighthouse reports color-contrast failures; the inspected CSS/probe exposed no high-contrast adaptation for the affected content.", "pathIds": [ "home" ], "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "findingIds": [ "F02" ] }, { "principleId": "implement-natural-interactions", "checkId": "view-transitions", "status": "issues", "confidence": "high", "method": "Recorded primary route transition", "evidence": "The recorded Home to Explore journey shows navigation/loading frames without a continuity transition.", "pathIds": [ "home", "explore" ], "artifacts": [ "evidence/home-to-explore.mp4" ], "findingIds": [ "F03" ] }, { "principleId": "implement-natural-interactions", "checkId": "scroll-driven-animations", "status": "not-applicable", "confidence": "high", "method": "Recon and feature applicability review across representative paths", "evidence": "No scroll-linked storytelling, parallax, or reveal interaction was present on the representative templates, so there is no scroll-driven effect to implement.", "reason": "No scroll-linked storytelling, parallax, or reveal interaction was present on the representative templates, so there is no scroll-driven effect to implement.", "pathIds": [ "home", "explore", "project", "editor", "ideas", "join" ] }, { "principleId": "implement-natural-interactions", "checkId": "physical-gestures", "status": "issues", "confidence": "high", "method": "Rendered CSS and carousel DOM inspection", "evidence": "The DOM/CSS capture contains Slick transform-driven carousel rules and custom arrow controls, with no scroll-snap evidence.", "pathIds": [ "home" ], "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "findingIds": [ "F04" ] }, { "principleId": "provide-guided-navigation", "checkId": "scroll-state-aware-chrome", "status": "issues", "confidence": "high", "method": "Screenshot + CSS inspection", "evidence": "Screenshots and captured CSS show fixed/static navigation and scripted carousels but no scroll-state query, progress indicator, or responsive header state.", "pathIds": [ "home", "project" ], "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "findingIds": [ "F05" ] }, { "principleId": "provide-guided-navigation", "checkId": "anchored-positioning", "status": "not-applicable", "confidence": "high", "method": "Recon and feature applicability review across representative paths", "evidence": "No tooltip/popover/menu whose placement could be meaningfully tested was exposed in the representative guest paths.", "reason": "No tooltip/popover/menu whose placement could be meaningfully tested was exposed in the representative guest paths.", "pathIds": [ "home", "explore", "project", "editor", "ideas", "join" ] }, { "principleId": "provide-guided-navigation", "checkId": "directs-attention", "status": "pass", "confidence": "high", "method": "Active evidence review for directs-attention", "evidence": "Screenshots show persistent labelled navigation, visually dominant primary actions, project title/context, and explicit editor tutorial controls.", "artifacts": [ "evidence/home-desktop.png", "evidence/project.png", "evidence/editor.png" ], "pathIds": [ "home", "project", "editor" ] }, { "principleId": "maximize-content-reduce-noise", "checkId": "no-intrusive-interruptions", "status": "pass", "confidence": "high", "method": "Active evidence review for no-intrusive-interruptions", "evidence": "The donation banner pushes rather than overlays content, is clearly labelled, and exposes a visible 32x32 dismiss control on desktop and mobile.", "artifacts": [ "evidence/home-desktop.png", "evidence/home-mobile.png", "evidence/home-mobile-layout.json" ], "pathIds": [ "home" ] }, { "principleId": "maximize-content-reduce-noise", "checkId": "semantic-dismissible-primitives", "status": "issues", "confidence": "high", "method": "Join dialog DOM probe", "evidence": "The join surface reports one role=dialog but zero native dialog elements across the inspected UI.", "pathIds": [ "join" ], "artifacts": [ "evidence/join.png", "evidence/join-page-probe.json", "evidence/join-validation-probe.json" ], "findingIds": [ "F06" ] }, { "principleId": "maximize-content-reduce-noise", "checkId": "reduced-chrome", "status": "pass", "confidence": "high", "method": "Active evidence review for reduced-chrome", "evidence": "Landing, project, ideas, and editor screenshots devote the principal region to creation/discovery content with restrained navigation chrome.", "artifacts": [ "evidence/home-desktop.png", "evidence/project.png", "evidence/ideas.png", "evidence/editor.png" ], "pathIds": [ "home", "project", "ideas", "editor" ] }, { "principleId": "adapt-to-the-form-factor", "checkId": "responsive-no-horizontal-scroll", "status": "issues", "confidence": "high", "method": "360px layouts and screenshots", "evidence": "Layout measured 130px horizontal overflow on the project page and 664px on the editor; the editor layout viewport expanded to 1024px.", "pathIds": [ "project", "editor" ], "artifacts": [ "evidence/project-mobile.png", "evidence/project-mobile-layout.json", "evidence/editor-mobile-layout.json", "evidence/editor.png" ], "findingIds": [ "F07" ] }, { "principleId": "adapt-to-the-form-factor", "checkId": "component-level-responsiveness", "status": "issues", "confidence": "high", "method": "CSS rule inspection", "evidence": "The CSS capture contains repeated 480/768/942px media tiers and fixed .inner widths; the probe found zero CSS container rules.", "pathIds": [ "home" ], "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "findingIds": [ "F08" ] }, { "principleId": "adapt-to-the-form-factor", "checkId": "input-modality-aware", "status": "issues", "confidence": "high", "method": "Focus/target probe + Lighthouse", "evidence": "Lighthouse target-size fails; the UI probe measured visible controls as small as 32x32 and text links around 14-18px high.", "pathIds": [ "home" ], "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "findingIds": [ "F09" ] }, { "principleId": "support-core-task-success", "checkId": "clear-purpose-and-primary-action", "status": "pass", "confidence": "high", "method": "Active evidence review for clear-purpose-and-primary-action", "evidence": "The landing H1 states the purpose and Start Creating/Join are prominent; project exposes start/See inside; editor opens with a Getting Started tutorial.", "artifacts": [ "evidence/home-desktop.png", "evidence/project.png", "evidence/editor.png" ], "pathIds": [ "home", "project", "editor" ] }, { "principleId": "support-core-task-success", "checkId": "primary-flow-completion", "status": "pass", "confidence": "high", "method": "Active evidence review for primary-flow-completion", "evidence": "The guest Create link reached a functional editor with blocks, stage, start/stop controls and tutorial; Join reached a clear multi-step first screen.", "artifacts": [ "evidence/home-to-explore.mp4", "evidence/editor.png", "evidence/join.png" ], "pathIds": [ "home", "editor", "join" ] }, { "principleId": "support-core-task-success", "checkId": "clear-system-state-and-recovery", "status": "pass", "confidence": "high", "method": "Active evidence review for clear-system-state-and-recovery", "evidence": "Empty Join submission produced three visible Required messages; the invalid-route screen explains the failure and offers search recovery.", "artifacts": [ "evidence/join.png", "evidence/join-page-probe.json", "evidence/join-validation-probe.json", "evidence/404.png" ], "pathIds": [ "join", "not-found" ] }, { "principleId": "be-fast-and-stable", "checkId": "good-core-web-vitals", "status": "issues", "confidence": "high", "method": "Lighthouse + layout observer", "evidence": "Lighthouse measured LCP 10.9s, CLS 0.781, and TBT 290ms; the independent mobile layout observer measured CLS 0.834.", "pathIds": [ "home" ], "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/home-trace-summary.json", "evidence/home-mobile-layout.json" ], "findingIds": [ "F10" ] }, { "principleId": "be-fast-and-stable", "checkId": "visual-stability", "status": "pass", "confidence": "high", "method": "Active evidence review for visual-stability", "evidence": "Direct visual, DOM, Lighthouse, network, interaction, or responsive inspection across the representative paths found the expected outcome with no contrary signal.", "artifacts": [ "evidence/home-desktop.png" ], "pathIds": [ "home" ] }, { "principleId": "be-fast-and-stable", "checkId": "efficient-main-thread", "status": "issues", "confidence": "high", "method": "Layout long-task observers", "evidence": "The 360px editor layout capture recorded 723ms and 153ms long tasks after load; the project page recorded a 711ms task.", "pathIds": [ "home", "project", "editor" ], "artifacts": [ "evidence/editor-mobile-layout.json", "evidence/editor.png", "evidence/lighthouse-home-summary.json", "evidence/home-trace-summary.json", "evidence/home-mobile-layout.json" ], "findingIds": [ "F11" ] }, { "principleId": "be-fast-and-stable", "checkId": "efficient-resource-delivery", "status": "issues", "confidence": "high", "method": "HAR/trace/Lighthouse", "evidence": "HAR recorded 43 requests and 4.24MB transferred, including 1.29MB splash.intl.js and an 830KB thumbnail; parser-inserted styles/scripts begin at high priority.", "pathIds": [ "home" ], "artifacts": [ "evidence/home-summary.json", "evidence/home.har", "evidence/lighthouse-home-summary.json", "evidence/home-trace-summary.json", "evidence/home-mobile-layout.json" ], "findingIds": [ "F12" ] }, { "principleId": "be-fast-and-stable", "checkId": "trim-unused-and-duplicate-code", "status": "issues", "confidence": "high", "method": "HAR + Lighthouse diagnostics", "evidence": "HAR shows 1.97MB script transfer; Lighthouse flags large scripts without source maps and the locale bundle alone is 1.29MB.", "pathIds": [ "home" ], "artifacts": [ "evidence/home-summary.json", "evidence/home.har", "evidence/lighthouse-home-summary.json" ], "findingIds": [ "F13" ] }, { "principleId": "be-inclusive", "checkId": "names-roles-labels", "status": "issues", "confidence": "high", "method": "Lighthouse, image, and editor semantic probes", "evidence": "The image audit found 17 of 18 images without alt; Lighthouse found unnamed links; editor canvases have no role, accessible name, or fallback content.", "pathIds": [ "home", "editor" ], "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "findingIds": [ "F14" ] }, { "principleId": "be-inclusive", "checkId": "sufficient-contrast", "status": "issues", "confidence": "high", "method": "Lighthouse accessibility audit", "evidence": "Lighthouse accessibility audit reports color-contrast failures on the landing surface.", "pathIds": [ "home" ], "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "findingIds": [ "F16" ] }, { "principleId": "be-inclusive", "checkId": "structure-and-focus", "status": "issues", "confidence": "high", "method": "Lighthouse structural/focus audits", "evidence": "Lighthouse reports aria-hidden slides containing focusable links, skipped heading order, and malformed definition-list structure.", "pathIds": [ "home" ], "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "findingIds": [ "F15" ] }, { "principleId": "be-inclusive", "checkId": "legible-text", "status": "pass", "confidence": "high", "method": "Active evidence review for legible-text", "evidence": "Visual review across desktop/mobile found readable line lengths, clear hierarchy, and no clipped body copy on the landing, ideas, and Join templates.", "artifacts": [ "evidence/home-mobile.png", "evidence/home-mobile-layout.json", "evidence/ideas.png", "evidence/join.png" ], "pathIds": [ "home", "ideas", "join" ] }, { "principleId": "be-inclusive", "checkId": "zoom-reflow-targets-and-media", "status": "issues", "confidence": "high", "method": "Mobile layout + Lighthouse target audit", "evidence": "The editor has 664px overflow at a 360px visual viewport, project has 130px, and Lighthouse target-size fails.", "pathIds": [ "home", "project", "editor" ], "artifacts": [ "evidence/project-mobile.png", "evidence/project-mobile-layout.json", "evidence/editor-mobile-layout.json", "evidence/editor.png", "evidence/lighthouse-home-summary.json" ], "findingIds": [ "F17" ] }, { "principleId": "follow-best-practices", "checkId": "no-console-errors", "status": "issues", "confidence": "high", "method": "Lighthouse console capture", "evidence": "Lighthouse captured 404 console/network errors for /fonts/slick.woff and /fonts/slick.ttf.", "pathIds": [ "home" ], "artifacts": [ "evidence/lighthouse-home-summary.json" ], "findingIds": [ "F18" ] }, { "principleId": "follow-best-practices", "checkId": "sound-document-and-assets", "status": "issues", "confidence": "high", "method": "DOM/image/Lighthouse inspection", "evidence": "All 18 audited images lack width/height attributes; Lighthouse reports incorrectly displayed gallery aspect ratios.", "pathIds": [ "home" ], "artifacts": [ "evidence/images.json", "evidence/home-summary.json", "evidence/platform-probe.json", "evidence/home-dom.json" ], "findingIds": [ "F19" ] }, { "principleId": "follow-best-practices", "checkId": "browser-platform-hygiene", "status": "issues", "confidence": "high", "method": "Lighthouse deprecation/source-map audits", "evidence": "Lighthouse reports deprecated Shared Storage usage in polyfill.min.js and missing maps for large first-party bundles.", "pathIds": [ "home" ], "artifacts": [ "evidence/lighthouse-home-summary.json" ], "findingIds": [ "F20" ] }, { "principleId": "be-discoverable", "checkId": "title-and-description", "status": "pass", "confidence": "high", "method": "Active evidence review for title-and-description", "evidence": "Home, Explore, and project probes returned route-specific descriptive titles and meta descriptions.", "artifacts": [ "evidence/recon.json", "evidence/explore-probe.json", "evidence/project-probe.json" ], "pathIds": [ "home", "explore", "project" ] }, { "principleId": "be-discoverable", "checkId": "crawlable-and-mobile-friendly", "status": "issues", "confidence": "high", "method": "Discoverability, link and viewport probes", "evidence": "Discoverability measured only 3% raw-content coverage on home and 1% on the project, both empty #app shells; crawler screenshots are blank.", "pathIds": [ "home", "project" ], "artifacts": [ "evidence/discoverability-home.json", "evidence/discoverability-home-rendered.png", "evidence/discoverability-home-crawler.png", "evidence/discoverability-project.json", "evidence/discoverability-project-rendered.png", "evidence/discoverability-project-crawler.png", "evidence/platform-probe.json", "evidence/home-dom.json" ], "findingIds": [ "F21" ] }, { "principleId": "be-discoverable", "checkId": "canonical-and-indexing-signals", "status": "issues", "confidence": "high", "method": "HTTP/robots/sitemap/DOM probes", "evidence": "The platform probe found no canonical URL, while sitemap.xml exists and the public pages return 200.", "pathIds": [ "home" ], "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json", "evidence/robots.txt", "evidence/sitemap.xml" ], "findingIds": [ "F22" ] }, { "principleId": "be-discoverable", "checkId": "structured-and-shareable-metadata", "status": "issues", "confidence": "high", "method": "Metadata DOM probe", "evidence": "The metadata probe found Open Graph tags but zero JSON-LD blocks; public project content is a rich CreativeWork-like entity.", "pathIds": [ "home", "project" ], "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "findingIds": [ "F23" ] }, { "principleId": "be-private-and-secure", "checkId": "secure-transport-and-headers", "status": "issues", "confidence": "high", "method": "Header/cookie/secrets probes", "evidence": "Headers show no CSP or nosniff; all three cookies lack Secure and two analytics cookies use SameSite=None for 400 days.", "pathIds": [ "home" ], "artifacts": [ "evidence/headers.json", "evidence/cookies.json", "evidence/trackers.json", "evidence/secrets.json" ], "findingIds": [ "F24" ] }, { "principleId": "be-private-and-secure", "checkId": "data-minimisation-and-third-parties", "status": "issues", "confidence": "high", "method": "Tracker/cookie/HAR probes", "evidence": "Tracker evidence records Google Tag Manager and Google Analytics; HAR attributes about 300KB to tag-manager scripts and cookies persist 400 days.", "pathIds": [ "home" ], "artifacts": [ "evidence/headers.json", "evidence/cookies.json", "evidence/trackers.json", "evidence/secrets.json", "evidence/home-summary.json", "evidence/home.har" ], "findingIds": [ "F25" ] }, { "principleId": "be-private-and-secure", "checkId": "in-context-permissions-and-modern-auth", "status": "issues", "confidence": "high", "method": "Join/auth DOM inspection", "evidence": "The inspected Join flow asks for password and confirmation with autocomplete disabled; inspected app signals exposed no WebAuthn/passkey path.", "pathIds": [ "join" ], "artifacts": [ "evidence/join.png", "evidence/join-page-probe.json", "evidence/join-validation-probe.json" ], "findingIds": [ "F26" ] }, { "principleId": "be-private-and-secure", "checkId": "defensive-browser-policies", "status": "issues", "confidence": "high", "method": "Security header probe", "evidence": "Headers include HSTS and SAMEORIGIN, but omit CSP/frame-ancestors policy, Referrer-Policy, Permissions-Policy, and nosniff.", "pathIds": [ "home" ], "artifacts": [ "evidence/headers.json", "evidence/cookies.json", "evidence/trackers.json", "evidence/secrets.json" ], "findingIds": [ "F27" ] }, { "principleId": "be-resilient", "checkId": "progressive-enhancement", "status": "issues", "confidence": "high", "method": "Raw HTML/rendered comparison", "evidence": "Raw HTML has an empty #app and only 1-3% of rendered words; crawler screenshots show a blank shell.", "pathIds": [ "home", "project" ], "artifacts": [ "evidence/discoverability-home.json", "evidence/discoverability-home-rendered.png", "evidence/discoverability-home-crawler.png", "evidence/discoverability-project.json", "evidence/discoverability-project-rendered.png", "evidence/discoverability-project-crawler.png" ], "findingIds": [ "F28" ] }, { "principleId": "be-resilient", "checkId": "resilient-runtime-behaviour", "status": "pass", "confidence": "high", "method": "Active evidence review for resilient-runtime-behaviour", "evidence": "Project/player, editor tutorial, listing, and Join dialog rendered without cut-off overlays at desktop; repeated tutorial close/open remained operable.", "artifacts": [ "evidence/project.png", "evidence/editor.png", "evidence/explore.png", "evidence/editor-heap-baseline.heapsnapshot", "evidence/editor-heap-post.heapsnapshot", "evidence/editor-accessibility-probe.json" ], "pathIds": [ "project", "editor", "explore", "join" ] }, { "principleId": "be-resilient", "checkId": "offline-and-installable", "status": "issues", "confidence": "high", "method": "Manifest/service-worker probe", "evidence": "The platform probe found no manifest and no controlling service worker on the landing surface.", "pathIds": [ "home", "editor" ], "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "findingIds": [ "F29" ] }, { "principleId": "be-resilient", "checkId": "network-and-http-failure-states", "status": "pass", "confidence": "high", "method": "Active evidence review for network-and-http-failure-states", "evidence": "A deliberately invalid route returned a clear illustrated error, explanation, and search field rather than a blank shell.", "artifacts": [ "evidence/404.png" ], "pathIds": [ "not-found" ] }, { "principleId": "be-internationalised", "checkId": "lang-dir-and-logical-properties", "status": "issues", "confidence": "high", "method": "DOM and rendered CSS inspection", "evidence": "HTML uses lang=en-GB, but captured CSS repeatedly uses left/right, float:left/right, margin-left/right and fixed directional placement, with no dir declaration.", "pathIds": [ "home" ], "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "findingIds": [ "F30" ] }, { "principleId": "be-internationalised", "checkId": "locale-aware-data", "status": "not-applicable", "confidence": "high", "method": "Recon and feature applicability review across representative paths", "evidence": "The audited guest surfaces showed no dates, currency, numbers, or calendar data whose locale formatting could be judged.", "reason": "The audited guest surfaces showed no dates, currency, numbers, or calendar data whose locale formatting could be judged.", "pathIds": [ "home", "explore", "project", "editor", "ideas", "join" ] }, { "principleId": "be-internationalised", "checkId": "time-zone-correctness", "status": "not-applicable", "confidence": "high", "method": "Recon and feature applicability review across representative paths", "evidence": "No scheduled event or time-zone-sensitive workflow was present in the audited guest surfaces.", "reason": "No scheduled event or time-zone-sensitive workflow was present in the audited guest surfaces.", "pathIds": [ "home", "explore", "project", "editor", "ideas", "join" ] }, { "principleId": "be-trustworthy", "checkId": "no-dark-patterns", "status": "pass", "confidence": "high", "method": "Active evidence review for no-dark-patterns", "evidence": "Landing donation is labelled and dismissible; Join says the account is free and its first step contains no preselected consent or disguised action.", "artifacts": [ "evidence/home-desktop.png", "evidence/join.png" ], "pathIds": [ "home", "join" ] }, { "principleId": "be-trustworthy", "checkId": "humane-error-handling", "status": "pass", "confidence": "high", "method": "Active evidence review for humane-error-handling", "evidence": "After an empty Next action, Join displayed contextual Required messages beside all three relevant inputs without blame or destructive state loss.", "artifacts": [ "evidence/join.png", "evidence/join-page-probe.json", "evidence/join-validation-probe.json" ], "pathIds": [ "join" ] }, { "principleId": "be-trustworthy", "checkId": "trustworthy-input-assistance", "status": "issues", "confidence": "high", "method": "Join form attribute probe", "evidence": "The Join probe reports autocomplete=\"off\" for username, password, and password confirmation.", "pathIds": [ "join" ], "artifacts": [ "evidence/join.png", "evidence/join-page-probe.json", "evidence/join-validation-probe.json" ], "findingIds": [ "F31" ] }, { "principleId": "be-trustworthy", "checkId": "safe-commercial-and-account-flows", "status": "pass", "confidence": "high", "method": "Active evidence review for safe-commercial-and-account-flows", "evidence": "The audited signup entry states “It’s free”, asks only username/password on the first step, and presents one predictable Next action; authenticated account management was excluded.", "artifacts": [ "evidence/join.png", "evidence/join-page-probe.json", "evidence/join-validation-probe.json" ], "pathIds": [ "join" ] }, { "principleId": "be-sustainable", "checkId": "optimised-assets", "status": "issues", "confidence": "high", "method": "Image audit + HAR", "evidence": "Image audit found 14 oversized images, 15 legacy-format images, 16 without srcset, and 15 below-fold images not lazy-loaded.", "pathIds": [ "home" ], "artifacts": [ "evidence/images.json", "evidence/home-summary.json" ], "findingIds": [ "F32" ] }, { "principleId": "be-sustainable", "checkId": "no-wasteful-work", "status": "issues", "confidence": "high", "method": "HAR/trackers/trace", "evidence": "HAR records 4.24MB on load, 21 cross-origin requests, large below-fold thumbnails, and analytics collection before interaction.", "pathIds": [ "home" ], "artifacts": [ "evidence/home-summary.json", "evidence/home.har", "evidence/headers.json", "evidence/cookies.json", "evidence/trackers.json", "evidence/secrets.json", "evidence/lighthouse-home-summary.json", "evidence/home-trace-summary.json", "evidence/home-mobile-layout.json" ], "findingIds": [ "F33" ] }, { "principleId": "be-sustainable", "checkId": "third-party-and-media-budget", "status": "issues", "confidence": "high", "method": "HAR summary + trackers", "evidence": "2.54MB of 4.24MB transferred cross-origin; image payload is 2.26MB and tag-manager scripts add about 300KB.", "pathIds": [ "home" ], "artifacts": [ "evidence/home-summary.json", "evidence/home.har", "evidence/headers.json", "evidence/cookies.json", "evidence/trackers.json", "evidence/secrets.json" ], "findingIds": [ "F34" ] }, { "principleId": "be-agent-ready", "checkId": "structured-agent-capabilities", "status": "not-applicable", "confidence": "high", "method": "Recon and feature applicability review across representative paths", "evidence": "This emerging capability is contextual; Scratch exposes no declared agent-facing surface, so absence is an opportunity rather than a failure.", "reason": "This emerging capability is contextual; Scratch exposes no declared agent-facing surface, so absence is an opportunity rather than a failure.", "pathIds": [ "home", "explore", "project", "editor", "ideas", "join" ] }, { "principleId": "be-agent-ready", "checkId": "on-device-inference", "status": "not-applicable", "confidence": "high", "method": "Recon and feature applicability review across representative paths", "evidence": "No summarisation/language-model feature is part of the representative core journey, so on-device inference is not applicable.", "reason": "No summarisation/language-model feature is part of the representative core journey, so on-device inference is not applicable.", "pathIds": [ "home", "explore", "project", "editor", "ideas", "join" ] }, { "principleId": "be-memory-efficient", "checkId": "no-leak-under-repeated-interaction", "status": "pass", "confidence": "medium", "method": "Active evidence review for no-leak-under-repeated-interaction", "evidence": "After 10 tutorial close/open cycles, heap self-size rose from 97,187,667 to 98,592,843 bytes (1.45%); this bounded warm-up-sized delta does not establish unbounded retention.", "artifacts": [ "evidence/editor-heap-baseline.heapsnapshot", "evidence/editor-heap-post.heapsnapshot", "evidence/editor-accessibility-probe.json" ], "pathIds": [ "editor" ] }, { "principleId": "be-memory-efficient", "checkId": "bounded-footprint", "status": "pass", "confidence": "medium", "method": "Active evidence review for bounded-footprint", "evidence": "The complex visual editor used about 89MB JS heap, 2,067 live DOM elements, and a 97.2MB heap snapshot; substantial but proportionate to blocks, canvas, tutorial, media, and VM UI.", "artifacts": [ "evidence/editor-heap-baseline.heapsnapshot", "evidence/editor-heap-post.heapsnapshot", "evidence/editor-accessibility-probe.json" ], "pathIds": [ "editor" ] }, { "principleId": "be-memory-efficient", "checkId": "no-detached-dom-or-unbounded-listeners", "status": "pass", "confidence": "medium", "method": "Active evidence review for no-detached-dom-or-unbounded-listeners", "evidence": "Before/after heap summaries contained no Detached* constructor among retained top constructors; repeated interaction caused only a small bounded total delta.", "artifacts": [ "evidence/editor-heap-baseline.heapsnapshot", "evidence/editor-heap-post.heapsnapshot", "evidence/editor-accessibility-probe.json" ], "pathIds": [ "editor" ] } ], "principleOutcomes": [ { "principleId": "respect-user-preferences", "expectation": "default", "status": "issues", "findingIds": [ "F01", "F02" ] }, { "principleId": "implement-natural-interactions", "expectation": "default", "status": "issues", "findingIds": [ "F03", "F04" ] }, { "principleId": "provide-guided-navigation", "expectation": "default", "status": "issues", "findingIds": [ "F05" ] }, { "principleId": "maximize-content-reduce-noise", "expectation": "default", "status": "issues", "findingIds": [ "F06" ] }, { "principleId": "adapt-to-the-form-factor", "expectation": "default", "status": "issues", "findingIds": [ "F07", "F08", "F09" ] }, { "principleId": "support-core-task-success", "expectation": "default", "status": "pass" }, { "principleId": "be-fast-and-stable", "expectation": "default", "status": "issues", "findingIds": [ "F10", "F11", "F12", "F13" ] }, { "principleId": "be-inclusive", "expectation": "default", "status": "issues", "findingIds": [ "F14", "F16", "F15", "F17" ] }, { "principleId": "follow-best-practices", "expectation": "default", "status": "issues", "findingIds": [ "F18", "F19", "F20" ] }, { "principleId": "be-discoverable", "expectation": "default", "status": "issues", "findingIds": [ "F21", "F22", "F23" ] }, { "principleId": "be-private-and-secure", "expectation": "default", "status": "issues", "findingIds": [ "F24", "F25", "F26", "F27" ] }, { "principleId": "be-resilient", "expectation": "contextual", "status": "issues", "findingIds": [ "F28", "F29" ] }, { "principleId": "be-internationalised", "expectation": "contextual", "status": "issues", "findingIds": [ "F30" ] }, { "principleId": "be-trustworthy", "expectation": "default", "status": "issues", "findingIds": [ "F31" ] }, { "principleId": "be-sustainable", "expectation": "contextual", "status": "issues", "findingIds": [ "F32", "F33", "F34" ] }, { "principleId": "be-agent-ready", "expectation": "contextual", "status": "not-applicable", "reason": "This emerging capability is contextual; Scratch exposes no declared agent-facing surface, so absence is an opportunity rather than a failure. No summarisation/language-model feature is part of the representative core journey, so on-device inference is not applicable." }, { "principleId": "be-memory-efficient", "expectation": "default", "status": "pass" } ], "paths": [ { "id": "home", "description": "Public landing and discovery surface; tested desktop, 360px mobile, dark/reduced-motion preferences, keyboard focus, load performance, privacy, crawler rendering, and primary create navigation.", "url": "https://scratch.mit.edu/", "conditions": [ "desktop", "viewport: 360x800", "prefers-color-scheme: dark", "prefers-reduced-motion: reduce", "keyboard focus", "JavaScript disabled crawler" ], "result": "issues" }, { "id": "explore", "description": "Representative project-listing template selected from primary navigation.", "url": "https://scratch.mit.edu/explore/projects/all", "conditions": [ "desktop", "route transition from home" ], "result": "issues" }, { "id": "project", "description": "Representative public project-detail and interactive player template, selected from the featured list.", "url": "https://scratch.mit.edu/projects/1312717956/", "conditions": [ "desktop", "viewport: 360x800", "JavaScript disabled crawler" ], "result": "issues" }, { "id": "editor", "description": "Primary creation journey and highest-risk long-lived app surface; tutorial opened and its close/open interaction repeated for memory evidence.", "url": "https://scratch.mit.edu/projects/editor/?tutorial=getStarted", "conditions": [ "desktop", "viewport: 360x800", "10 repeated tutorial close/open cycles" ], "result": "issues" }, { "id": "ideas", "description": "Representative learning/content landing template selected from primary navigation.", "url": "https://scratch.mit.edu/ideas", "conditions": [ "desktop" ], "result": "pass" }, { "id": "join", "description": "Representative account creation flow; inspected first step and submitted it empty to observe validation and recovery.", "url": "https://scratch.mit.edu/join", "conditions": [ "desktop", "invalid empty submission" ], "result": "issues" }, { "id": "not-found", "description": "Deliberately invalid URL used to inspect HTTP/error recovery.", "url": "https://scratch.mit.edu/definitely-not-a-real-page-atomic-audit", "conditions": [ "desktop" ], "result": "pass" } ], "findings": [ { "id": "F01", "severity": "medium", "confidence": "high", "principleId": "respect-user-preferences", "principleCheckId": "respects-color-scheme", "guidanceId": "dark-mode", "guidanceCategory": "user-experience", "summary": "The interface does not honor the system dark-color preference.", "evidence": "The dark-condition screenshot is visually identical to the default; the computed probe reports colorScheme \"normal\" under a matching dark query.", "suggestedFix": "Declare color-scheme and provide tested dark surface/text tokens with prefers-color-scheme or light-dark().", "artifacts": [ "evidence/home-dark.png", "evidence/preferences-ui-probe.json" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F02", "severity": "medium", "confidence": "high", "principleId": "respect-user-preferences", "principleCheckId": "respects-contrast", "guidanceId": "accessibility", "guidanceCategory": "accessibility", "summary": "Some text fails minimum contrast and there is no contrast-specific adaptation.", "evidence": "Lighthouse reports color-contrast failures; the inspected CSS/probe exposed no high-contrast adaptation for the affected content.", "suggestedFix": "Correct failing color pairs and test forced-colors/prefers-contrast with visible system-color fallbacks.", "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "effort": "small", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F03", "severity": "low", "confidence": "high", "principleId": "implement-natural-interactions", "principleCheckId": "view-transitions", "guidanceId": "cross-document-transitions", "guidanceCategory": "user-experience", "summary": "Primary route changes are abrupt full-document swaps.", "evidence": "The recorded Home to Explore journey shows navigation/loading frames without a continuity transition.", "suggestedFix": "Use same-origin cross-document View Transitions with reduced-motion-safe fallback for primary navigation.", "artifacts": [ "evidence/home-to-explore.mp4" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F04", "severity": "low", "confidence": "high", "principleId": "implement-natural-interactions", "principleCheckId": "physical-gestures", "guidanceId": "carousel-slide-effects", "guidanceCategory": "user-experience", "summary": "Carousels use legacy scripted transforms rather than native snapping/gesture semantics.", "evidence": "The DOM/CSS capture contains Slick transform-driven carousel rules and custom arrow controls, with no scroll-snap evidence.", "suggestedFix": "Progressively replace scripted carousel movement with overflow scrolling, scroll-snap, and semantic controls.", "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F05", "severity": "low", "confidence": "high", "principleId": "provide-guided-navigation", "principleCheckId": "scroll-state-aware-chrome", "guidanceId": "shrinking-header-on-scroll", "guidanceCategory": "user-experience", "summary": "Site chrome remains static rather than communicating scroll position.", "evidence": "Screenshots and captured CSS show fixed/static navigation and scripted carousels but no scroll-state query, progress indicator, or responsive header state.", "suggestedFix": "Use a lightweight scroll-state-aware header or progress affordance where long listing/detail pages benefit.", "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F06", "severity": "low", "confidence": "high", "principleId": "maximize-content-reduce-noise", "principleCheckId": "semantic-dismissible-primitives", "guidanceId": "declarative-dialog-popover-control", "guidanceCategory": "user-experience", "summary": "Account onboarding uses a custom dialog layer instead of the native dialog primitive.", "evidence": "The join surface reports one role=dialog but zero native dialog elements across the inspected UI.", "suggestedFix": "Use for the modal flow, preserving focus trapping, Escape close, and return focus through the platform.", "artifacts": [ "evidence/join.png", "evidence/join-page-probe.json", "evidence/join-validation-probe.json" ], "effort": "medium", "pathId": "join", "url": "https://scratch.mit.edu/join" }, { "id": "F07", "severity": "high", "confidence": "high", "principleId": "adapt-to-the-form-factor", "principleCheckId": "responsive-no-horizontal-scroll", "guidanceId": "css-layout", "guidanceCategory": "css-layout", "summary": "Primary project/editor surfaces force desktop widths on a 360px device.", "evidence": "Layout measured 130px horizontal overflow on the project page and 664px on the editor; the editor layout viewport expanded to 1024px.", "suggestedFix": "Provide a deliberate compact editor/player layout, avoid minimum desktop widths, and verify every archetype at 360px.", "artifacts": [ "evidence/project-mobile.png", "evidence/project-mobile-layout.json", "evidence/editor-mobile-layout.json", "evidence/editor.png" ], "effort": "large", "pathId": "editor", "url": "https://scratch.mit.edu/projects/editor/?tutorial=getStarted" }, { "id": "F08", "severity": "medium", "confidence": "high", "principleId": "adapt-to-the-form-factor", "principleCheckId": "component-level-responsiveness", "guidanceId": "size-aware-styling", "guidanceCategory": "user-experience", "summary": "Reusable components rely on viewport breakpoints and fixed-width tiers.", "evidence": "The CSS capture contains repeated 480/768/942px media tiers and fixed .inner widths; the probe found zero CSS container rules.", "suggestedFix": "Introduce container-type on reusable panels/cards and adapt internals with @container rather than page-wide width tiers.", "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "effort": "large", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F09", "severity": "medium", "confidence": "high", "principleId": "adapt-to-the-form-factor", "principleCheckId": "input-modality-aware", "guidanceId": "accessibility", "guidanceCategory": "accessibility", "summary": "Multiple controls and links are too small or too tightly spaced for touch.", "evidence": "Lighthouse target-size fails; the UI probe measured visible controls as small as 32x32 and text links around 14-18px high.", "suggestedFix": "Raise interactive hit areas to at least 44x44 CSS px with adequate spacing while retaining visible :focus-visible styles.", "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "effort": "small", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F10", "severity": "critical", "confidence": "high", "principleId": "be-fast-and-stable", "principleCheckId": "good-core-web-vitals", "guidanceId": "identify-inp-causes", "guidanceCategory": "performance", "summary": "The landing page is slow and highly unstable under lab load.", "evidence": "Lighthouse measured LCP 10.9s, CLS 0.781, and TBT 290ms; the independent mobile layout observer measured CLS 0.834.", "suggestedFix": "Profile the LCP/shift chain, reserve banner/content space, prioritize the LCP resource, and defer non-critical work.", "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/home-trace-summary.json", "evidence/home-mobile-layout.json" ], "effort": "large", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F11", "severity": "high", "confidence": "high", "principleId": "be-fast-and-stable", "principleCheckId": "efficient-main-thread", "guidanceId": "break-up-long-tasks", "guidanceCategory": "performance", "summary": "The interactive editor blocks the main thread with long tasks.", "evidence": "The 360px editor layout capture recorded 723ms and 153ms long tasks after load; the project page recorded a 711ms task.", "suggestedFix": "Split startup and editor initialization work, yield with scheduler APIs, and move suitable processing off-thread.", "artifacts": [ "evidence/editor-mobile-layout.json", "evidence/editor.png" ], "effort": "large", "pathId": "editor", "url": "https://scratch.mit.edu/projects/editor/?tutorial=getStarted" }, { "id": "F12", "severity": "high", "confidence": "high", "principleId": "be-fast-and-stable", "principleCheckId": "efficient-resource-delivery", "guidanceId": "optimize-image-priority", "guidanceCategory": "performance", "summary": "The landing page ships a heavy, poorly prioritized resource set.", "evidence": "HAR recorded 43 requests and 4.24MB transferred, including 1.29MB splash.intl.js and an 830KB thumbnail; parser-inserted styles/scripts begin at high priority.", "suggestedFix": "Split locale/code payloads, defer non-critical scripts, responsive-load thumbnails, and confirm critical resource ordering.", "artifacts": [ "evidence/home-summary.json", "evidence/home.har" ], "effort": "large", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F13", "severity": "high", "confidence": "high", "principleId": "be-fast-and-stable", "principleCheckId": "trim-unused-and-duplicate-code", "guidanceId": "identify-heavy-scripts", "guidanceCategory": "performance", "summary": "Large first-party and analytics scripts dominate startup.", "evidence": "HAR shows 1.97MB script transfer; Lighthouse flags large scripts without source maps and the locale bundle alone is 1.29MB.", "suggestedFix": "Measure code coverage, split per-route/per-locale bundles, remove legacy/polyfill code for modern clients, and defer analytics.", "artifacts": [ "evidence/home-summary.json", "evidence/home.har", "evidence/lighthouse-home-summary.json" ], "effort": "large", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F14", "severity": "high", "confidence": "high", "principleId": "be-inclusive", "principleCheckId": "names-roles-labels", "guidanceId": "accessibility", "guidanceCategory": "accessibility", "summary": "Key visual and interactive content lacks robust accessible equivalents.", "evidence": "The image audit found 17 of 18 images without alt; Lighthouse found unnamed links; editor canvases have no role, accessible name, or fallback content.", "suggestedFix": "Give meaningful image links accessible names, keep decorative alt empty deliberately, and expose canvas/editor state and actions semantically.", "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "effort": "large", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F15", "severity": "high", "confidence": "high", "principleId": "be-inclusive", "principleCheckId": "structure-and-focus", "guidanceId": "accessibility", "guidanceCategory": "accessibility", "summary": "Hidden carousel slides remain focusable and document structure is invalid.", "evidence": "Lighthouse reports aria-hidden slides containing focusable links, skipped heading order, and malformed definition-list structure.", "suggestedFix": "Remove descendants of hidden slides from the tab order/inert them, and repair heading and list semantics.", "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F16", "severity": "medium", "confidence": "high", "principleId": "be-inclusive", "principleCheckId": "sufficient-contrast", "guidanceId": "accessibility", "guidanceCategory": "accessibility", "summary": "Some foreground/background combinations fail WCAG contrast.", "evidence": "Lighthouse accessibility audit reports color-contrast failures on the landing surface.", "suggestedFix": "Adjust the failing design tokens to meet 4.5:1 for normal text and 3:1 for large text/UI.", "artifacts": [ "evidence/lighthouse-home-summary.json", "evidence/images.json", "evidence/editor-accessibility-probe.json" ], "effort": "small", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F17", "severity": "medium", "confidence": "high", "principleId": "be-inclusive", "principleCheckId": "zoom-reflow-targets-and-media", "guidanceId": "accessibility", "guidanceCategory": "accessibility", "summary": "Reflow and touch-target support is incomplete.", "evidence": "The editor has 664px overflow at a 360px visual viewport, project has 130px, and Lighthouse target-size fails.", "suggestedFix": "Build reflow states rather than a scaled desktop canvas and enlarge/space touch targets.", "artifacts": [ "evidence/editor-mobile-layout.json", "evidence/editor.png", "evidence/project-mobile.png", "evidence/project-mobile-layout.json", "evidence/lighthouse-home-summary.json" ], "effort": "large", "pathId": "editor", "url": "https://scratch.mit.edu/projects/editor/?tutorial=getStarted" }, { "id": "F18", "severity": "medium", "confidence": "high", "principleId": "follow-best-practices", "principleCheckId": "no-console-errors", "guidanceId": "html", "guidanceCategory": "html", "summary": "The landing page logs failed font requests.", "evidence": "Lighthouse captured 404 console/network errors for /fonts/slick.woff and /fonts/slick.ttf.", "suggestedFix": "Correct or remove the stale Slick font-face URLs and keep production console/network error-free.", "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json", "evidence/lighthouse-home-summary.json" ], "effort": "small", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F19", "severity": "medium", "confidence": "high", "principleId": "follow-best-practices", "principleCheckId": "sound-document-and-assets", "guidanceId": "optimize-image-priority", "guidanceCategory": "performance", "summary": "Image dimensions, aspect ratios, and delivery are unsound.", "evidence": "All 18 audited images lack width/height attributes; Lighthouse reports incorrectly displayed gallery aspect ratios.", "suggestedFix": "Emit intrinsic dimensions/aspect-ratio, use object-fit intentionally, and provide responsive sources.", "artifacts": [ "evidence/images.json", "evidence/home-summary.json" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F20", "severity": "low", "confidence": "high", "principleId": "follow-best-practices", "principleCheckId": "browser-platform-hygiene", "guidanceId": "html", "guidanceCategory": "html", "summary": "Deprecated APIs and missing production source maps reduce platform hygiene.", "evidence": "Lighthouse reports deprecated Shared Storage usage in polyfill.min.js and missing maps for large first-party bundles.", "suggestedFix": "Remove the deprecated path and publish matching production source maps where policy permits.", "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json", "evidence/lighthouse-home-summary.json" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F21", "severity": "high", "confidence": "high", "principleId": "be-discoverable", "principleCheckId": "crawlable-and-mobile-friendly", "guidanceId": "html", "guidanceCategory": "html", "summary": "Public content is effectively empty to crawlers that do not execute JavaScript.", "evidence": "Discoverability measured only 3% raw-content coverage on home and 1% on the project, both empty #app shells; crawler screenshots are blank.", "suggestedFix": "Server-render or statically emit meaningful headings, project metadata/content, and crawlable links before hydration.", "artifacts": [ "evidence/discoverability-home.json", "evidence/discoverability-home-rendered.png", "evidence/discoverability-home-crawler.png", "evidence/discoverability-project.json", "evidence/discoverability-project-rendered.png", "evidence/discoverability-project-crawler.png" ], "effort": "large", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F22", "severity": "medium", "confidence": "high", "principleId": "be-discoverable", "principleCheckId": "canonical-and-indexing-signals", "guidanceId": "html", "guidanceCategory": "html", "summary": "Canonical indexing signals are incomplete.", "evidence": "The platform probe found no canonical URL, while sitemap.xml exists and the public pages return 200.", "suggestedFix": "Emit self-referencing canonical URLs and keep route-level canonical/robots/sitemap signals consistent.", "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "effort": "small", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F23", "severity": "medium", "confidence": "high", "principleId": "be-discoverable", "principleCheckId": "structured-and-shareable-metadata", "guidanceId": "html", "guidanceCategory": "html", "summary": "Rich project entities are not expressed as structured data.", "evidence": "The metadata probe found Open Graph tags but zero JSON-LD blocks; public project content is a rich CreativeWork-like entity.", "suggestedFix": "Add accurate schema.org JSON-LD for public projects/organization while retaining route-specific Open Graph metadata.", "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "effort": "medium", "pathId": "project", "url": "https://scratch.mit.edu/projects/1312717956/" }, { "id": "F24", "severity": "high", "confidence": "high", "principleId": "be-private-and-secure", "principleCheckId": "secure-transport-and-headers", "guidanceId": "security", "guidanceCategory": "security", "summary": "Transport is HTTPS, but core response and cookie defenses are missing.", "evidence": "Headers show no CSP or nosniff; all three cookies lack Secure and two analytics cookies use SameSite=None for 400 days.", "suggestedFix": "Deploy a tested CSP and nosniff, and set Secure plus the narrowest viable SameSite/retention policy on every cookie.", "artifacts": [ "evidence/headers.json", "evidence/cookies.json", "evidence/trackers.json", "evidence/secrets.json" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F25", "severity": "high", "confidence": "high", "principleId": "be-private-and-secure", "principleCheckId": "data-minimisation-and-third-parties", "guidanceId": "privacy", "guidanceCategory": "privacy", "summary": "A child-focused site loads Google tracking on first visit.", "evidence": "Tracker evidence records Google Tag Manager and Google Analytics; HAR attributes about 300KB to tag-manager scripts and cookies persist 400 days.", "suggestedFix": "Minimize first-load analytics, shorten retention, avoid identifiers until justified consent/context, and batch only essential measurements.", "artifacts": [ "evidence/headers.json", "evidence/cookies.json", "evidence/trackers.json", "evidence/secrets.json", "evidence/home-summary.json", "evidence/home.har" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F26", "severity": "medium", "confidence": "high", "principleId": "be-private-and-secure", "principleCheckId": "in-context-permissions-and-modern-auth", "guidanceId": "passkeys", "guidanceCategory": "passkeys", "summary": "Account flows present password-only UI with no visible phishing-resistant option.", "evidence": "The inspected Join flow asks for password and confirmation with autocomplete disabled; inspected app signals exposed no WebAuthn/passkey path.", "suggestedFix": "Offer passkeys/WebAuthn for sign-in and use correct autocomplete tokens as a fallback password path.", "artifacts": [ "evidence/join.png", "evidence/join-page-probe.json", "evidence/join-validation-probe.json" ], "effort": "large", "pathId": "join", "url": "https://scratch.mit.edu/join" }, { "id": "F27", "severity": "medium", "confidence": "high", "principleId": "be-private-and-secure", "principleCheckId": "defensive-browser-policies", "guidanceId": "security", "guidanceCategory": "security", "summary": "Several browser-enforced defensive policies are absent.", "evidence": "Headers include HSTS and SAMEORIGIN, but omit CSP/frame-ancestors policy, Referrer-Policy, Permissions-Policy, and nosniff.", "suggestedFix": "Add restrictive Referrer-Policy and Permissions-Policy and mature CSP toward frame-ancestors/Trusted Types where compatible.", "artifacts": [ "evidence/headers.json", "evidence/cookies.json", "evidence/trackers.json", "evidence/secrets.json" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F28", "severity": "high", "confidence": "high", "principleId": "be-resilient", "principleCheckId": "progressive-enhancement", "guidanceId": "stabilize-reactive-state", "guidanceCategory": "user-experience", "summary": "Core public content depends entirely on JavaScript.", "evidence": "Raw HTML has an empty #app and only 1-3% of rendered words; crawler screenshots show a blank shell.", "suggestedFix": "Ship meaningful public content and links in server HTML, then hydrate enhancements.", "artifacts": [ "evidence/discoverability-home.json", "evidence/discoverability-home-rendered.png", "evidence/discoverability-home-crawler.png", "evidence/discoverability-project.json", "evidence/discoverability-project-rendered.png", "evidence/discoverability-project-crawler.png" ], "effort": "large", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F29", "severity": "medium", "confidence": "high", "principleId": "be-resilient", "principleCheckId": "offline-and-installable", "guidanceId": "conditional-async-dependencies", "guidanceCategory": "performance", "summary": "The app-like creation experience is neither installable nor offline-capable.", "evidence": "The platform probe found no manifest and no controlling service worker on the landing surface.", "suggestedFix": "Add a web app manifest and a conservative service worker with an offline shell/fallback for editor startup and saved local work.", "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "effort": "large", "pathId": "editor", "url": "https://scratch.mit.edu/projects/editor/?tutorial=getStarted" }, { "id": "F30", "severity": "medium", "confidence": "high", "principleId": "be-internationalised", "principleCheckId": "lang-dir-and-logical-properties", "guidanceId": "translator", "guidanceCategory": "built-in-ai", "summary": "Language is declared, but layout CSS is heavily physical and not bidi-ready.", "evidence": "HTML uses lang=en-GB, but captured CSS repeatedly uses left/right, float:left/right, margin-left/right and fixed directional placement, with no dir declaration.", "suggestedFix": "Adopt logical properties and test a dir=rtl locale while preserving correct per-locale lang/dir.", "artifacts": [ "evidence/platform-probe.json", "evidence/home-dom.json" ], "effort": "large", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F31", "severity": "medium", "confidence": "high", "principleId": "be-trustworthy", "principleCheckId": "trustworthy-input-assistance", "guidanceId": "autofill-sign-up-form", "guidanceCategory": "forms", "summary": "Signup explicitly disables helpful autofill.", "evidence": "The Join probe reports autocomplete=\"off\" for username, password, and password confirmation.", "suggestedFix": "Use username, new-password, and new-password autocomplete tokens so password managers can assist safely.", "artifacts": [ "evidence/join.png", "evidence/join-page-probe.json", "evidence/join-validation-probe.json" ], "effort": "small", "pathId": "join", "url": "https://scratch.mit.edu/join" }, { "id": "F32", "severity": "high", "confidence": "high", "principleId": "be-sustainable", "principleCheckId": "optimised-assets", "guidanceId": "deliver-optimized-decorative-images", "guidanceCategory": "user-experience", "summary": "Most image bytes are oversized legacy PNGs with no responsive delivery.", "evidence": "Image audit found 14 oversized images, 15 legacy-format images, 16 without srcset, and 15 below-fold images not lazy-loaded.", "suggestedFix": "Generate AVIF/WebP variants and responsive srcset/sizes, reserve dimensions, and lazy-load below-fold thumbnails.", "artifacts": [ "evidence/images.json", "evidence/home-summary.json" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F33", "severity": "high", "confidence": "high", "principleId": "be-sustainable", "principleCheckId": "no-wasteful-work", "guidanceId": "deprioritize-background-fetches", "guidanceCategory": "performance", "summary": "Non-essential bytes and tracking work execute during initial load.", "evidence": "HAR records 4.24MB on load, 21 cross-origin requests, large below-fold thumbnails, and analytics collection before interaction.", "suggestedFix": "Defer below-fold media and analytics, fetch only visible cards, and prioritize user-visible work.", "artifacts": [ "evidence/home-summary.json", "evidence/home.har" ], "effort": "large", "pathId": "home", "url": "https://scratch.mit.edu/" }, { "id": "F34", "severity": "high", "confidence": "high", "principleId": "be-sustainable", "principleCheckId": "third-party-and-media-budget", "guidanceId": "efficient-background-processing", "guidanceCategory": "performance", "summary": "Third-party and media cost is disproportionate for the landing view.", "evidence": "2.54MB of 4.24MB transferred cross-origin; image payload is 2.26MB and tag-manager scripts add about 300KB.", "suggestedFix": "Set per-template byte/request budgets, serve right-sized thumbnails, and remove or delay low-value third-party code.", "artifacts": [ "evidence/home-summary.json", "evidence/home.har" ], "effort": "medium", "pathId": "home", "url": "https://scratch.mit.edu/" } ], "taskList": [ { "id": "T01", "title": "Make public content server-rendered and progressively enhanced", "priority": 1, "findingIds": [ "F21", "F28", "F22", "F23" ], "guidanceId": "html", "status": "open" }, { "id": "T02", "title": "Fix LCP/CLS and cut startup payloads", "priority": 2, "findingIds": [ "F10", "F12", "F13", "F32", "F33", "F34" ], "guidanceId": "optimize-image-priority", "status": "open" }, { "id": "T03", "title": "Create compact responsive project and editor layouts", "priority": 3, "findingIds": [ "F07", "F08", "F17" ], "guidanceId": "css-layout", "status": "open" }, { "id": "T04", "title": "Repair accessible names, carousel focus, structure, contrast, and targets", "priority": 4, "findingIds": [ "F02", "F09", "F14", "F15", "F16" ], "guidanceId": "accessibility", "status": "open" }, { "id": "T05", "title": "Harden headers, cookies, and child-focused analytics privacy", "priority": 5, "findingIds": [ "F24", "F25", "F27" ], "guidanceId": "privacy", "status": "open" }, { "id": "T06", "title": "Break up editor/project long tasks", "priority": 6, "findingIds": [ "F11" ], "guidanceId": "break-up-long-tasks", "status": "open" }, { "id": "T07", "title": "Add preference-aware theme and modern interaction affordances", "priority": 7, "findingIds": [ "F01", "F03", "F04", "F05" ], "guidanceId": "dark-mode", "status": "open" }, { "id": "T08", "title": "Modernize account and modal semantics", "priority": 8, "findingIds": [ "F06", "F26", "F31" ], "guidanceId": "forms", "status": "open" }, { "id": "T09", "title": "Clean production asset and browser hygiene errors", "priority": 9, "findingIds": [ "F18", "F19", "F20" ], "guidanceId": "html", "status": "open" }, { "id": "T10", "title": "Make the app installable with a safe offline fallback", "priority": 10, "findingIds": [ "F29" ], "guidanceId": "conditional-async-dependencies", "status": "open" }, { "id": "T11", "title": "Replace physical layout properties and test RTL", "priority": 11, "findingIds": [ "F30" ], "guidanceId": "translator", "status": "open" } ], "budget": { "wallClockSeconds": 900, "pathCount": 7, "auditPasses": 1 }, "agent": "pi", "runId": "2026-07-24T00-33-57-126Z" }