Vocabulary Highlighter — Learn While Reading & Watching

Highlight unknown words on any website and YouTube. 12 languages. Flashcards, spaced repetition, word frequency. No account needed.

Learn vocabulary from the articles and YouTube videos you already enjoy. Highlight words you haven't marked as known, find the ones you keep meeting, and choose what to practice next. No account needed. READ, NOTICE, PRACTICE 1. Choose the language you're learning, open a webpage, and click Activate. 2. Click a highlighted word to check its meaning. Use Know word when you recognize it. 3. Open Learn new words → Last page to review unfamiliar words from your latest highlighted page. 4. Choose Practice to add a word to Flashcards, then review it with spaced repetition. FOCUS ON WORDS FROM YOUR OWN READING Your personal dictionary carries across pages. See which unfamiliar words appear repeatedly, mark words you already know, and choose vocabulary that matters to you. Words you select with Practice are available in Flashcards without waiting for a frequency threshold. Frequently encountered words can also enter your deck after 10 encounters. Again, Good, and Easy schedule your next review. USE THE SAME DICTIONARY ON YOUTUBE Highlight words in YouTube captions while you watch. Turn on CC subtitles, then activate the extension. Words you mark as known while reading are remembered when you encounter them in captions, too. 12 LANGUAGES Learn English, Spanish, French, German, Italian, Portuguese, Russian, Turkish, Arabic, Hindi, Japanese, or Korean. Each language has its own dictionary, learning statistics, and flashcards. TOOLS FOR YOUR READING ROUTINE - A setup quiz to mark common words you already know, available in six languages - An estimate of familiar vocabulary on each page, reading streaks, and learning charts - Customizable highlight colors - CSV import and export for your word lists - Dictionary sync through Chrome - A warning when a page clearly uses a different language from the one you've selected - Optional related-form suggestions for supported English and French singular/plural pairs - A separate highlight for words you've marked as known in another language using the same writing system TRANSLATIONS AND COMPATIBILITY English words use English dictionary definitions from dictionaryapi.dev. For other learning languages, Chrome's built-in Translator can translate words into your selected native language on supported desktop Chrome versions. The first use may require a language-pack download. If built-in translation is unavailable, you can open the word in Google Translate. Highlighting works with supported webpage text and YouTube CC captions. Protected browser pages and subtitles embedded in video images cannot be highlighted. PRIVACY No Vocabulary Highlighter account is required. Your dictionary and learning history are stored locally in Chrome; your dictionary can also sync through your Chrome profile. Highlighting and supported built-in translations happen in your browser. English definition lookups send the selected word to dictionaryapi.dev. Google Translate opens only when you click its link. Product-usage events are sent to Google Analytics with a randomly generated identifier. WHAT'S NEW IN 0.5.1 - Highlighting avoids interactive text so website buttons, links, and forms remain usable. - More reliable dictionary updates and Chrome sync across tabs and languages. - Flashcards preserve scheduled reviews and handle repeated clicks correctly. - Quiz progress is saved separately for each language. - Fixes for word-list imports and last-page review.