Translate a subtitle file
Takes an SRT or VTT file and rewrites every line in another language, keeping the timings exactly as they were. The model is downloaded to your device and runs there — the file never leaves this tab.
Drop an SRT or VTT file here
SRT · VTT — timings are kept exactly as they are
Pressing the button downloads about 608 MB of runtime and model. It is fetched once and kept by your browser — the next file starts straight away.
Plain sentences come out well; idioms often do not. Read it through before you publish it.
Where does my subtitle file go?
Nowhere. It is read inside this browser tab and never uploaded. Subtitles are usually a full transcript of what was said in a meeting, a lecture or an interview, which makes them one of the more revealing files you own.
How good is the translation?
Good enough to follow, not good enough to publish unedited. Plain sentences come out well. Idioms are where it slips: "let's wrap this up" came back as something closer to "let's get this started" in both Spanish and German. It also gets the occasional article or plural wrong. Treat it as a solid first draft that a human still reads through.
Why this model and not a bigger one?
We measured five. The obvious pick, a four-billion-parameter translation model, is gated behind manual approval upstream and its terms require passing use restrictions on to whoever receives the weights — which we cannot do for an anonymous browser. Another strong candidate is licensed for non-commercial use only. The small single-pair models are properly licensed but have no English-to-Korean build at all, and the cheap multilingual one produced Zulu when asked for Korean. What is left is an MIT-licensed model that does 100 languages in any direction and actually works.
Why does it take so long?
About a second and a half per subtitle line, on the processor. This model will not run on the graphics card — we tried, and it either refuses to start or collapses into repeating one word forever. So the time is real, and the page tells you the estimate before you start rather than after. You can stop it partway; the lines already done are kept and the rest stay in the original language.
Do the timings change?
No. Every line keeps the exact start and end it came in with, because only the text is touched. That is also why translated lines can run longer on screen than the original — some languages simply need more words, and we do not re-time to hide it.
Can I translate the subtitles I just generated?
Yes, and that is the intended path. Generate subtitles from your video with the subtitle tool, download the SRT, and drop it here. Both steps run in this browser, so the recording and its transcript never touch a server.
Other tools
- Compress videoShrink an MP4 in your browser. No 30MB toolchain to download — your device does the work.
- Audio extractorPull the sound out of a video. Nothing is re-encoded, so nothing is lost.
- Video to GIFTurn a clip into a looping GIF. Your device does the work — nothing is uploaded.
- Video trimmerCut a clip out of a video without re-encoding it. Nothing is lost, and it takes seconds.