YouTube and Twitch Video Helpers
YouTube and Twitch use small, site-specific content helpers on top of normal DNR blocking. Cosmetic hiding targets dedicated ad-only elements; the player region and real content are never touched. See Cosmetic Filtering for the full policy.
YouTube
Video ads are removed at the source. A MAIN-world script (content/yt-inpage.ts) runs in the page's own context at document_start and deletes the ad instructions (adPlacements, adSlots, playerAds) from YouTube's player responses — both the inline ytInitialPlayerResponse (first video, via an accessor installed before it is assigned) and the /youtubei/v1/player fetch (every subsequent video). With no ads to schedule, the player starts the real video immediately; streamingData and everything else is left intact. This is uBlock Origin's approach and is much cleaner than fast-forwarding. It honors the off switch, allowlist, and YouTube toggle via a config message from the isolated content script, and reports removed ads back for stats.
On top of that source-level pruning, the isolated content script:
- Detects
youtube.comhostnames. - Hides feed, masthead, display, and companion ad elements (
ytd-ad-slot-renderer,ytd-display-ad-renderer,#masthead-ad, and the grid cells that wrap them) without hiding real videos, comments, Shorts, or recommendations. - Clicks visible ad skip buttons and fast-forwards any
ad-showingpre/mid-roll — a safety net for ads that slip past the pruner. - Dismisses the "ad blockers violate Terms" enforcement popup — hides the modal and shared backdrop, restores scrolling, and resumes playback, only when the enforcement message is present.
- Records estimated video seconds saved when an ad is pruned, skipped, or fast-forwarded.
These behaviors are tested with cached YouTube-like pages served as www.youtube.com in Bun WebView, asserting ads are hidden and skipped while the real feed video, comments, <video>, and skip button stay visible and playback continues. test/youtube-prune.test.ts additionally runs the built yt-inpage.js in real Chromium and asserts ads are stripped from both inline and fetched player responses while streamingData survives.
Twitch
The content script:
- Detects
twitch.tvhostnames. - Hides Twitch's ad-only affordances — the "Leave feedback for this Ad" / "Learn more about this ad" buttons and the anti-adblock nag overlay. (Twitch now stitches video ads into the stream server-side, so the old display-banner containers no longer exist and were dropped.)
- Records estimated video seconds saved when Twitch video-ad markers appear — the markers stay visible because the ad is the live stream itself.
- Uses throttled mutation scans so stream chat and live page updates stay responsive.
Twitch changes often, so the implementation focuses on ad-affordance hiding plus marker detection instead of brittle player rewrites.
Limits
These sites change often. The implementation favors precise, ad-only selectors, visible skip-button automation, and passive marker detection over fragile playback hacks or broad DOM hiding that risk breaking normal use.