Direction
Pick 中文 → EN to translate Chinese into English, or EN → 中文 for the reverse. The Swap button exchanges source and translation.
First-time download
The first translation in each direction downloads the model files (~50 MB zh→en, ~33 MB en→zh) and the Bergamot WebAssembly runtime. We don't host these — they stream directly from
Mozilla's Firefox Translations
bucket. The browser cache + service worker keep them around so subsequent translations are instant and work offline.
Shortcuts
- Cmd/Ctrl + Enter — translate immediately.
- The textarea auto-translates after a short pause once the engine is ready.
Privacy
Translation runs entirely in your browser. The source text never leaves the page. Mozilla's bucket only sees the model-file GETs.
Quality
These are the same models Firefox uses for in-browser translation. Quality is solid for everyday prose, weaker on idioms, names, and very short fragments. Use the
Dictionary for word-level lookups.
Got a question? Stuck?
Drop into the
Mandarin Stack Discord
— share tips, request features, get help.