Zamak

Watch YouTube with dual-language subtitles side by side. Bookmark captions, view all bookmarks. For language learners.

Zamak adds a floating subtitle panel to YouTube that shows two languages side by side — perfect for language learners. Features: • Dual-language captions — see Korean + English (or any available pair) at the same time • Click any caption line to seek the video to that timestamp • Auto-scroll keeps the current caption visible as the video plays • Resizable panel — drag to adjust width • Floating action button to toggle the panel on/off • Bookmark caption lines — select text to create bookmarks with notes • Bookmark editor — review and edit bookmarks with AI prompt support (copy context to clipboard, paste into your favorite LLM) • Bookmarks page — click the extension icon to see all videos with bookmarks • Settings dropdown — configure caption alignment, auto-scroll, and export data • Adapts to YouTube's dark and light theme automatically • Works with both manual and auto-generated YouTube subtitles • Auto-translated captions — works even when only one language track is available • No account required, no data collection — everything runs locally How it works: When you visit a YouTube video, Zamak fetches the available subtitle tracks and displays them in a side-by-side panel overlaid on the page. The panel syncs with video playback in real time. Select any text to bookmark it, then use the built-in editor to add translations and notes — or copy an AI prompt to get help from your favorite LLM. Click the Zamak icon to see all your bookmarked videos at a glance. Supported: Any YouTube video with subtitles. Works best with videos that have two or more language tracks, but also supports auto-translated captions for single-language videos. The project is open source and the source code is available on https://github.com/hi-ogawa/ytsub-v5.