YouTube / Public web reference / 2026.09
Evidence and coverage
Every claim has a source boundary. Observed appearance, measured geometry and local implementation choices receive different labels.
All entries shown
Evidence types
| Label | Meaning |
|---|---|
| Observed | Visible in a dated browser capture with route, state and viewport. |
| Measured | Computed CSS or geometry read by a repeatable browser probe. |
| First-party documentation | A public YouTube or Google source states a behavior. This does not prove that every rollout or account currently exposes it. |
| Source-derived reconstruction | Public delivered CSS or assets support the local specimen. Production composition may remain unverified. |
| Reconstructed | A complete local contract informed by evidence, with its own testable behavior. |
| Original addition | A guide, test fixture or extension created for this package. It must not be mistaken for production YouTube behavior. |
Source ledger
| Source | URL | Evidence and confidence |
|---|---|---|
| live-home-signed-out | https://www.youtube.com/ | Desktop guide, search controls, signed-out prompt and no-history home empty state. observed |
| live-search-signed-out | https://www.youtube.com/results?search_query=lofi | Query field, selected filter tab, filter chips, filters trigger, sponsored result and standard result metadata. observed |
| live-watch-signed-out | https://www.youtube.com/watch?v=jfKfPfyJRdk | Player controls expose labels and shortcuts, while this selected stream reports Video unavailable. observed |
| live-channel | https://www.youtube.com/@YouTube | Channel identity header, tab strip, description disclosure, subscribe action, shelf and card actions. observed |
| live-history-signed-out | https://www.youtube.com/feed/history | Signed-out history boundary, sign-in call to action and displayed clear/pause control labels. observed |
| help-keyboard-shortcuts | https://support.google.com/youtube/answer/7631406?hl=en | Keyboard shortcut table says new computer experience requires player click before shortcuts; specifies k, m, j/l, arrows, f, c, Shift+N/P and i. first-party documentation |
| help-screen-reader | https://support.google.com/youtube/answer/189278?hl=en-CA | Screen-reader guidance names search field, result metadata, settings menu, theater and full screen. first-party documentation |
| help-search-filters | https://support.google.com/youtube/answer/111997?hl=en-GB | Filters follow a search and can limit result type to video, Short, movie, playlist or channel. first-party documentation |
| help-recommendations-history | https://support.google.com/youtube/answer/6342839?hl=en | Feedback actions, fewer Shorts choice, and history effects on recommendations are documented; some require sign in. first-party documentation |
| help-playlists | https://support.google.com/youtube/answer/57792 | Save flow from a video or Short, privacy selection, confirmation message, playlist type chips and reorder contract. first-party documentation |
| help-shorts | https://support.google.com/youtube/answer/12319243?hl=en-uk | Left-rail Shorts opens a continuous feed; Shorts occur in home, search and channel shelves. first-party documentation |
| blog-shorts-update | https://blog.youtube/news-and-events/youtube-shorts-experience-updates-features/ | June 25, 2026 post announces staged Shorts-player updates, including Clear Screen and speed controls. first-party documentation |
| fresh-denominator-20260918 | https://www.youtube.com/ | Fourteen current Chromium route/viewport captures confirm the independently inventoried public route families. Home and Shorts retain session-sensitive content boundaries. observed |
Contract recovery
| Contract | Recovered information | Remaining uncertainty |
|---|---|---|
| player-input-contract | Click player before shortcuts in the new computer experience. k toggles play, m mute, j/l seek 10 seconds, seekbar arrows seek 5 seconds, f full screen, c captions, Shift+N/P playlist navigation and i miniplayer. Settings may contain speed, subtitles/CC and quality. | Control availability and playback state vary by video. The captured video is unavailable and cannot prove successful playback, captions or settings selection. |
| search-filter-contract | After a query produces results, a visible Filters trigger can refine results. The live row exposes role=tab with aria-selected, and the official help documents result type filters including Video, Short, Movie, Playlist and Channel. | The exact contents and order of the opened filter panel were not captured. |
| shorts-contract | Shorts appear in Home, search and channel shelves. Left-rail Shorts enters a player that continuously advances through a feed. The June 2026 blog says Clear Screen and speed controls roll out over time. | The individual Shorts player was not captured in Chromium; Clear Screen is a rollout statement, not a universal observed state. |
| playlist-contract | More > Save can open playlist selection or create-new-playlist flow, with name and privacy selection. A confirmation message appears after save. Playlist pages may offer All, Shorts and Videos chips, and reorder can use drag except Shorts-only playlists. | The signed-in dialog, confirmation and drag behavior are documented but not directly observed in this capture. |
| history-boundary | Signed-out history says it is not viewable and offers Sign in. Labels for clear/pause watch history and clear/pause search history remain visible. History and search controls influence recommendations when enabled. | Authenticated history listing, deletion confirmation and paused state were excluded. |
| channel-header-contract | Public header includes channel name and handle, subscriber and video counts, description disclosure, external-links disclosure, Subscribe, and tabs. Profile help says description is accessible in the channel header. | Studio customization, upload crop and publication flow require creator authentication. |
| appearance-contract | The public opened-state capture establishes an Appearance-menu Back control and a selected Light-theme check at 390px, corroborated at 1440px. The local Light/Dark selection, asset substitution, and localStorage persistence are a reconstructed local contract verified at both target widths. | The captured production state does not establish production persistence, every Appearance choice, or remote preference failure behavior. |
| premium-landing-contract | The public route resolved with responseStatus 200 and title YouTube Premium - YouTube at 390px, 768px, 1440px, and 1920px. Retained page HTML, viewport images, and accessibility snapshots establish the hero, public offer cards, Premium Lite card, benefit sections, membership comparison, final CTA, and seven-question FAQ. The visible offer amounts and trial language are dated observations from 2026-09-18, not current offer guarantees. CTA destinations were sign-in endpoints, so checkout, payment, entitlement, cancellation, and fulfillment remain unverified private purchase behavior. | 401/403 entries are failed subresources recorded in console output. They do not negate the top-level 200 response or the retained page content. Locale, eligibility, prices, promotions, and plan availability can vary. The sign-in destination does not establish checkout or account behavior. |
| css-source-and-local-contract-recovery | A web reference cannot claim CSS coverage from a stylesheet archive alone. Every settled component and its local reconstructed counterpart needs an explicit selector, condition, computed evidence, and comparison record. | The source CSS is minified and route-dependent. It does not prove private runtime composition, signed-in states, ads, captions, quality, cast, or every overlay. The source/local geometry report records unresolved comparable mismatches and intentional boundaries; any failed local part/state probe remains an open contract gap. |
Capture and coverage
Production evidence is stored outside the static publication root under evidence/. The published comparisons show representative source captures. The JSON ledgers record all captured routes, CSS sources, icon meanings, components and pattern states. A raw screenshot is appearance evidence; it cannot prove keyboard operation, source authority or unseen account behavior.
Current evaluation status: provisional. Local verification evidence is retained. Deployment checks are recorded in the assessment download; benchmark readiness requires the independent panel and canonical validator.
Open research boundaries
Personalized recommendations, subscriptions and history depend on a signed-in account. Playback can be unavailable on the capture host. Creator Studio and billing completion are separate authenticated tasks. First-party help and delivered sources are used for reconstruction; their limits stay visible in every affected example.