DeepLingo

DeepLingo turns the time you already spend on YouTube and Netflix into French vocabulary practice. While you watch, the extension overlays clickable subtitles over the player. Click any word to see its translation, IPA, examples, synonyms, and inflection — then save it with one click. WHAT YOU GET • Click-to-translate subtitles on YouTube and Netflix. The native player captions are hidden so you only see DeepLingo's interactive overlay. Click any word for an instant lookup. • Rich word cards. Each lookup shows the translation, IPA, part of speech, a CEFR level (A1–C2), synonyms and antonyms, and an example sentence from what you're watching — plus a button to hear the word when a pronunciation recording is available. • Sentence translation. Translate a whole subtitle line, not just single words — on-device when your browser supports it, otherwise via DeepLingo's translation service. • Dual subtitles. In the transcript sidebar, show the English translation under each French line and read along in both languages. • CEFR tier highlighting. Color words by their level, or hide everything outside a level range, so you focus on exactly the vocabulary you're ready for. • Saved-word fade. Words you've already saved appear faded in the overlay so your eye is naturally drawn to new vocabulary. • Save words with or without an account. Saved words live on this browser by default, so you can start immediately — no sign-up required. • Transcript sidebar (press T or click the ▤ icon). Browse every caption captured so far, search across them, jump to any line on YouTube, see saved words inline with their translations, and download the transcript as text or CSV. • Vocabulary export. Download your saved words as CSV (for Anki, Quizlet, spreadsheets) or plain text — with or without translations and source info. Export works whether you're signed in or not. • On-device-first translation. Words in our bundled French dictionary are looked up entirely on your device. For anything else, Chrome's built-in on-device translator (Chrome 138+) handles it with nothing leaving your browser; only when neither can, the specific word or phrase is sent to DeepLingo's translation service to translate it. FREE VS EXTENSION PLUS • Free: interactive subtitles, word lookups, transcript sidebar, local saves, and vocabulary export. Includes 20 machine-translations per day for words/sentences not covered on-device. • Extension Plus (or any DeepLingo subscription): cloud sync and backup of your saved words across devices, unlimited translations, and post-watch quizzes that review the words you saved from a video. Manage it at deeplingo.ca. PRIVACY We are very deliberate about what leaves your device: • We do not collect or store your subtitles. Captions are captured and kept in your browser. • We do not collect the URLs of pages you visit. • We do not log clicks, scrolls, focus, or any other behavioral data by default. Anonymous usage telemetry and crash reports are both opt-in (default OFF) and toggleable in Options. • The only text sent to our servers is (a) a word or phrase you actively translate when it can't be handled on your device — used only to return the translation, and (b) the vocabulary you save, once you sign in and sync. A saved entry is the French word, its translation, an optional source (show + timestamp), and the example sentence. Full policy: https://deeplingo.ca/privacy/extension HOW IT WORKS 1. Open any French YouTube or Netflix video and turn on French captions. 2. Click any word in the subtitle for a translation popup. 3. Click "+ Add to vocabulary" to save it (stays on this browser). 4. Open the transcript sidebar (T) for full-episode browsing, search, and dual subtitles. 5. Optional: subscribe at deeplingo.ca to sync your saved words across devices and unlock quizzes. SUPPORTED SITES • YouTube (any video with French captions, including auto-generated) • Netflix (any title with a French subtitle track) Works only with your own subscriptions. We never modify, scrape, or bypass any platform's content-protection mechanisms. TECHNICAL NOTES • Manifest V3 service worker, modern Chrome only (latest two versions supported). • Built with Preact; the overlay runs entirely in your browser. LIMITATIONS • French → English only for now. • Some Netflix titles deliver subtitles only as bitmap images; those cannot be intercepted and DeepLingo will simply not appear. • Click-to-seek from the sidebar works on YouTube; on Netflix, seeks initiated outside Netflix's own player trigger an "M7375" error, so this feature is hidden there. WHAT'S NEXT Prime Video support and additional language pairs beyond French → English are on the roadmap.