YouTube Loop

A minimal Chrome extension that loops a specified time range on YouTube and lets you slow down playback for shadowing / language practice.

Sibling project of netflix-loop — same UX, simpler internals (no DRM bridge needed).

Features

• Floating panel on any YouTube watch page (top-right, dim until hovered)
• Set a start/end time, click Loop — the player jumps back to start whenever it reaches end
• ● button next to each input grabs the current playback time (no typing)
• Time inputs accept any of: 1:23, 1:23:45, or raw seconds (83)
• Playback speed: 5 presets (0.5 / 0.75 / 1× / 1.25 / 1.5) plus a fine-adjust row — click −/+ for ±0.05 steps, or type a custom value in the input (range 0.25–2.00, e.g. 0.85). Pitch preserved.
• Loop range and speed are remembered per video (keyed by ?v= ID)
• Manually dragging the timeline outside the loop range turns the loop off (so you can scrub freely)
• Ad-aware: skips loop logic and mark buttons during ads (checks #movie_player.ad-showing); shows Ad playing… in the readout
• Survives video changes (re-binds via MutationObserver)
• Works in fullscreen (panel re-parents into the fullscreen element)

Install (load unpacked)

1. Open chrome://extensions
2. Enable Developer mode (top right)
3. Click Load unpacked and select this folder
4. Open any YouTube video — the panel appears in the top-right corner

To update after editing source: hit the refresh icon on the extension card in chrome://extensions, then reload the YouTube tab.

Usage

1. Play your video, scrub to the moment you want to loop from
2. Click ● next to Start to mark the current time
3. Scrub to the end of the segment, click ● next to End
4. Click Loop OFF to toggle it on
5. Pick a speed preset (e.g. 0.75) for slow shadowing
6. Click ⤴ to jump back to the start manually any time

Drag the timeline outside the marked range to disable the loop and watch normally.

Files

File	What it does
manifest.json	Manifest V3; injects on all youtube.com pages
content.js	Builds the panel, handles loop logic, ad detection, persistence
content.css	Panel styling (dark with YouTube red accent)

Notes

• Why simpler than Netflix Loop? YouTube doesn't gate <video>.currentTime writes behind DRM, so we can seek directly without bridging into a MAIN-world script.
• Loop boundary precision is ~±0.25s (timeupdate ~4Hz). Plenty for normal use.
• Only /watch?v=... URLs are supported. Shorts and embeds are out of scope.
• Permissions: storage and host_permissions for youtube.com. No analytics, no network calls.