How to use
- Drop your file(s) into the box above — or click it to browse.
- Conversion starts immediately; the tabs switch to a different output format.
- Click Download on each finished file — or Download all (.zip) for a batch. Nothing was uploaded at any point.
Why web players reject your ASS file
ASS is a full typesetting system built for desktop renderers like libass — browsers have never supported it and never will. The HTML5 <track> element, Video.js, JW Player and the rest of the web stack accept exactly one caption format: WebVTT. So putting a fansub archive, a lecture recording, or any ASS-subtitled video onto the web means this conversion.
The converter parses the [Events] section honoring the declared Format: field order, strips every {\...} override tag (positions, colors, karaoke — none of it renders in a browser anyway), converts \N to line breaks, re-sorts cues chronologically, and writes centisecond ASS timing as VTT's dot-millisecond timestamps.
| Feature | In ASS | After conversion |
|---|---|---|
| Dialogue text | Yes | Kept exactly (commas included) |
| Timing | Centiseconds | Dot milliseconds, same values |
| Line breaks \N | Yes | Real line breaks |
| Styling {\i1}, colors, fonts | Yes | Stripped (no browser support) |
| Positioning {\pos} | Yes | Removed — cues render at player default |
| Chronological order | Often unsorted | Sorted |
What about VTT styling?
WebVTT does have its own styling system (cue settings and ::cue CSS), but there is no faithful mapping from ASS typesetting — a {\pos(400,570)} sign translated literally would land in the wrong place on every player. This converter deliberately outputs plain, maximally compatible cues and leaves styling to your player's CSS, which is the approach that actually works across browsers.
When NOT to convert ASS to VTT
- Desktop playback — VLC and mpv render ASS natively with full styling; converting loses the typesetting for nothing.
- Karaoke and sign-heavy anime releases — the visual identity lives in the ASS tags; on the web those effects are gone regardless, but know what you're giving up.
- If your target accepts SRT — some platforms take SRT uploads; ASS → SRT is the more portable choice there.