Converting VTT to SBV gives you the same content in a different container. It runs in your browser: nothing is uploaded, there is no queue and no size limit.
What changes when you convert VTT to SBV
- Both formats are lossless: nothing in the picture or sound changes, only the container and the compression.
- Timing is preserved to the millisecond. Styling that SBV cannot express (positions, colours, karaoke effects) is removed; basic italics and bold are kept where the format allows.
When to convert, and when not to
Convert to SBV for YouTube captions. YouTube's caption export.
Keep VTT for video on websites. The web's subtitle format, required by HTML5 video.
How to convert VTT to SBV
- Drop your VTT file on the converter above, or click to choose. Several at once is fine.
- Check the options if you need them: shift timing (ms, ± to delay/advance).
- Click Convert, then Download. Nothing was sent anywhere, your browser did the work.
Questions
Is my VTT file uploaded?
No. The conversion runs in your browser with WebAssembly. There is no upload endpoint on this site. You can open your browser's Network tab, or go offline after the page loads, and it still works.
Is there a file size limit?
No fixed one. The limit is your device's memory: a large subtitles file on a phone is slower than on a laptop, but nothing is rejected for being big.
Is it free?
Yes, without an account, without a daily cap and without a watermark. Your device does the computing, so there is no server bill to pass on.
Will the quality drop?
No. SBV is lossless: the subtitles content is stored exactly.
Can I convert several files at once?
Yes. Drop them all; each is converted in turn and you can download them one by one or as a single ZIP.
Which engine does the conversion?
Subtitle engine, compiled to WebAssembly and running in your browser. First use downloads about 0 MB, cached afterwards.