Introducing LingoKeep: Learn Languages Watching YouTube — and Actually Remember
A Chrome extension that turns YouTube into a language classroom — dual subtitles, a click-any-word dictionary, one-click flashcards, and free spaced-repetition review. The plan we published before launch, kept on the record.
Update: LingoKeep has been on the Chrome Web Store since 3 August 2026 — install it here. It launched with four languages rather than two: Spanish, Japanese, French and German. The rest of this post is the plan exactly as we published it on 2 July, left unedited so you can still hold us to it.
We're building LingoKeep — a Chrome extension for learning languages while watching YouTube. It's not released yet; this post is us putting the plan on the record before launch, so you can hold us to it.
The problem
Watching native content is the most enjoyable way to learn a language, and YouTube has endless free content in every language. But the loop is broken: you watch, you half-understand, you look words up in another tab, and a week later you've forgotten all of them. Comprehension without retention.
What LingoKeep does
The whole product is one loop: Watch. Understand. Keep.
- Dual subtitles — the original language and an English translation together on the player, with sentence-level controls: replay this line, jump back a line, slow it down.
- Click-any-word dictionary — click a word in the subtitles for its dictionary form, reading, and meanings. Select several words to look up a whole phrase.
- One-click flashcards — save a word or phrase with its sentence, translation, and a timestamp back to the exact second of the video it came from.
- Free spaced-repetition review — every saved card comes back on an FSRS schedule, in the extension or on your phone at lingokeep.com/review. Listening-type cards replay the original clip as the card front.
- Anki export — Pro users can export their whole deck to CSV. Your cards are never locked in.
We're launching with Spanish and Japanese (interface in English). Two languages done properly — dictionaries, lemma lookup, Japanese segmentation and readings — beats twenty done badly.
What it costs
The learning loop is free forever: dual subtitles, the dictionary, FSRS review, and sync, with a 100-card deck. Pro ($4.99/mo or $39/yr) removes the card cap and adds Anki export, with AI-powered sentence explanations planned later.
Review is free on purpose. A spaced-repetition tool that paywalls the repetition part isn't a learning tool.
What it isn't (yet)
Honesty section. Today, LingoKeep:
- isn't released — the extension is in active development;
- doesn't support Netflix — YouTube first, because it's free and deep-linkable;
- supports two languages, not twenty.
Privacy stance
The extension runs only on youtube.com and lingokeep.com. We don't track your browsing or watch history — the only thing stored on our servers is the cards you explicitly save, plus your account email.
Try it
If this sounds like the tool you've been duct-taping together from three other apps, install LingoKeep — the whole learning loop, review included, is free up to a 100-card deck.