TV · Radio · Podcasts

Beta · Language Reactor for the open web

Watch & learn

Watch any YouTube video with side-by-side captions, click words for definitions, save them to a deck, and study at your level. Curated learner channels in 4 languages.

🃏 My saved words →

🇬🇧English

Starter videos

Channels worth following

🇯🇵日本語

Starter videos

Channels worth following

🇪🇸Español

Starter videos

Channels worth following

🇫🇷Français

Starter videos

Channels worth following

Phase 1 · what works today

  • YouTube IFrame player + side-by-side caption strip pulled from YT's public timedtext feed
  • Curated starter videos + recommended channels in 4 languages
  • Paste any YouTube URL or video ID to watch + read captions

Phase 2 · coming next

  • Click-to-define popovers (JMdict for 🇯🇵, Wiktionary for 🇪🇸/🇫🇷)
  • Furigana ふりがな over kanji via kuromoji.js
  • YouGlish-style word search across captioned videos