About Subgloss
Learn a language from the videos you already watch.
Subgloss replaces the subtitles on YouTube and Netflix with a line made for learners: each word's meaning in that sentence above it, the word being spoken highlighted, and the whole line translated underneath.
MEANINGS IN CONTEXT
Not a dictionary list: the meaning the word has in this line. Show meanings for the key words (the default), for every word, or only when you hover over one.
CLICK A WORD TO STUDY IT
The video pauses and a card shows the word's dictionary form, reading, part of speech and meaning. Hear it again from the video itself, slowed down, or in a clear voice. Shift-click to select a whole phrase. Step back and forward a line, or replay the one you just heard.
SAVE WORDS, EXPORT TO ANKI
Save a word with the sentence it came from, its translation and a link back to that moment in the video. Export your saved words as a CSV file or as a file Anki imports.
YOUR OWN AI, OR NONE AT ALL
• Use your own API key from Google Gemini (which has a free tier), OpenAI or Anthropic, or a model on your own computer (Ollama, LM Studio or another OpenAI-compatible server).
• Or use Chrome's built-in on-device AI, with no key at all, for Japanese and Spanish videos with meanings in English. Gemini Nano writes the meanings, Chrome's translator translates the lines, and a downloadable dictionary shows meanings straight away. Gemini Nano needs 22 GB of free disk space and 16 GB of memory or a 4 GB graphics card; on other computers the dictionary's meanings are used. On-device meanings are simpler than an AI service's, and Subgloss labels them so you know.
SAVED WORDS ON EVERY COMPUTER (OPTIONAL)
Sign in with your email address and a code we send you, no password, and your saved words appear on every computer where you sign in. Everything else works without an account.
GOOD TO KNOW
• The video needs subtitles in the language you are learning. On YouTube, auto-generated subtitles work too.
• Netflix support is in beta: switch subtitles on in Netflix's own menu first.
• Lines can be translated into 33 languages. Subgloss's own pages are in English.
• Switch Subgloss off for a site from its toolbar button, and make the text bigger or smaller from the video.
PRIVACY
No ads, no analytics, no tracking, and we never sell data. Subtitle text goes straight from your browser to the AI service you choose, using your own key; with on-device AI it never leaves your computer. If you sign in, we store your email address and your saved words, and you can delete them at any time from Options → Account. The full policy: https://subgloss.app/privacy
HELP
Write to support@subgloss.app.
CREDITS
Japanese dictionary: JMdict, © the Electronic Dictionary Research and Development Group, CC BY-SA 4.0. Spanish dictionary: Wiktionary's contributors, CC BY-SA 4.0, via wiktextract. Japanese word analysis: kuromoji.js (Apache-2.0).
Subgloss is made by MobilityArts Pty Ltd and is not affiliated with YouTube, Netflix, Google, OpenAI or Anthropic.