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Zenzu vs Language Reactor: YouTube Learning Compared

Facts checked against official sources on . Written by the Zenzu team — we build one of these tools, so our sources are listed below.

Choose Language Reactor if you mostly watch Netflix or YouTube on a desktop browser and want dual subtitles while you watch. Choose Zenzu if you want to learn on your phone as well as the web, and want words and phrases from videos, podcasts and articles to become flashcards that are reviewed with FSRS-5 spaced repetition — without exporting anything to another app.

Zenzu and Language Reactor compared feature by feature
Zenzu Language Reactor
What it is Language learning app with interactive transcripts and built-in spaced repetition Browser extension that adds dual subtitles and click-to-translate to video sites
Content YouTube, podcasts, articles, pasted text, photos of text Netflix and YouTube, plus text and books features on its website
Spaced repetition FSRS-5 built in No SRS scheduler; PhrasePump practice, and Pro exports saved words to Anki
AI Lisa, an AI coach replying in your language Lexa AI dictionary and an AI chat partner
Platforms iPhone and iPad (iOS 15+), web Chrome and Chromium-based desktop browsers

Where Language Reactor is the better choice

  • Netflix. Zenzu does not work with Netflix; Language Reactor was built for it.
  • Watching in place. The extension sits on top of the streaming site, so you never leave the player.
  • Sentence-mining into Anki. If you already run an Anki workflow, Pro’s export slots straight into it.

Where Zenzu is the better choice

  • Mobile. Language Reactor lives in a desktop browser; Zenzu runs on iPhone and iPad as well as the web.
  • The review loop is included. Saved words and phrases are scheduled with FSRS-5 inside the same app — no export step, no second tool to maintain.
  • Beyond video. Podcasts are transcribed so you can read along and save phrases, and articles or photos of text become vocabulary too.
  • Explanations in your language. Lisa and the interface speak English, Ukrainian, German, French, Spanish and Portuguese.

Bottom line

Language Reactor is an excellent subtitle layer for desktop viewing. Zenzu is a complete capture-and-review loop you can carry on your phone.

Sources