DualSub for All

Learn languages from what you watch, read and chat about: dual subtitles, a hover dictionary and live chat translation.

Learn a language from anything you watch, read or chat about. DualSub shows dual subtitles on YouTube, gives you a hover dictionary on any website and PDF, translates your chats live in the chat apps you already use, and keeps every word you save in one notebook with flashcards and AI grammar notes. One extension, one notebook, no account needed. WHO IT IS FOR • Learners who watch YouTube in English, Spanish, Japanese, Korean, Chinese and want to understand without pausing every sentence. • Students and professionals who read articles, documentation and PDFs in a foreign language. • People who chat with friends, customers or colleagues in another language. • Anyone tired of looking up the same word three times and still forgetting it. ▸ DUAL SUBTITLES ON YOUTUBE See the original subtitle and its translation at the same time, in any language pair YouTube offers. Hover a word to see its meaning; the video pauses while you look and resumes when you move away. Hide YouTube's own captions so nothing overlaps. ▸ CHAT MODE (new in 2.6) Chatting with someone in another language? Turn on Chat Mode in WhatsApp Web, Telegram Web, Messenger, Discord or Instagram Direct and every incoming message gets a translation line right under it. Type in your own language, press Tab to replace it with the translation, then send. Hover any word in a message to look it up and save it. Pause it per chat whenever you like. ▸ HOVER DICTIONARY ON ANY WEBSITE Turn on Reading Mode, hold Alt and hover a word to see its meaning and part of speech right where you read. Select a phrase or paragraph to translate it in place. ▸ PDF READER WITH LOOKUP Open online or local PDF files in DualSub's built-in reader and look up words the same way. Great for papers, textbooks and manuals. ▸ ONE-CLICK VOCABULARY NOTEBOOK Click a word to save it with its meaning, the exact sentence you found it in, a translation of that sentence and a link back to the video or page. Words are grouped by language and by day, so "today's Spanish words" is one click away. ▸ FLASHCARDS AND ANKI EXPORT Review with built-in flashcards (keyboard shortcuts included) or export to CSV for Anki. Back up and restore your notebook as JSON. ▸ AI GRAMMAR NOTES Get the grammar around each saved word, its word forms, common collocations and three fresh example sentences with translations. Included with Pro, or bring your own Gemini, OpenAI or Claude API key on the free plan. ▸ YOUR LANGUAGE, YOUR INTERFACE Meanings, saved words and AI notes follow the language you choose. Interface in English and Vietnamese, more coming. FREE vs PRO Free forever: dual subtitles, hover dictionary on web and PDF, PDF reader, flashcards, CSV export, up to 100 saved words, Chat Mode with 300 free message translations then 30 long messages a day (short messages always free). Pro ($3.99/month or $24.99/year): unlimited saved words, unlimited chat translation, sentence and paragraph translation, example sentences translated when you save, AI grammar notes with no setup. One license for 3 computers. 14-day money-back guarantee. PRIVACY Your notebook stays on your device. No account, no ads, no third-party tracking. Only the word, sentence or chat message you translate is sent to the translation service. Only anonymous feature-usage counts (numbers, no content) are sent to DualSub. Full policy: https://dualsubksai.github.io/dualsub/privacy/ Questions or ideas: dualsub.ksai@gmail.com