AI Subtitle Studio
Free tool

Convert ASS/SSA to WebVTT (.vtt)

Turn a styled fansub .ass file into standards-correct WebVTT for HTML5 video and web players — dialogue and timing kept, styling stripped.

Nothing stored afterward No account needed ASS/SSA (Advanced SubStation Alpha) → WebVTT

Your file is processed and sent straight back — never saved on our servers.

Prefer not to upload your file?

The AI Subtitle Studio desktop app has this same Tools section built in — plus AI transcription, translation and batch processing for a whole season at once, all running locally on your Mac or PC.

Get the desktop app
How it works

Upload ASS/SSA (Advanced SubStation Alpha), get WebVTT back

Upload one file

ASS/SSA (Advanced SubStation Alpha) — .ass,.ssa.

Converted instantly

Parsed and rewritten as WebVTT in memory, no queue and no waiting.

Download the result

The converted file downloads straight to your device.

About this conversion

Converting ASS/SSA (Advanced SubStation Alpha) to WebVTT

ASS/SSA carries rich styling — fonts, colors, positioning, karaoke — built for a dedicated subtitle renderer like VLC or mpv, not for a browser's native caption track. WebVTT is what HTML5 video and most web upload forms actually expect, and it has no way to represent ASS's override tags or its typesetting. Converting strips all of that and keeps the dialogue and its exact timing, rewritten with WebVTT's required WEBVTT header and period-decimal timestamps.

This is the conversion to reach for when you have a fansub or anime .ass file and need to upload captions to a website, embed them in an HTML5 <track> element, or use them anywhere WebVTT is the only format accepted — most video hosting platforms and learning tools included.

FAQ

Questions about this converter

What happens to karaoke timing and sign typesetting?
It's removed — WebVTT has no equivalent to ASS's per-syllable karaoke or positioned typesetting, so the output is plain dialogue text with its overall cue timing intact.
Will dialogue that overlapped with a sign translation look wrong?
Occasionally — if the ASS file relied on positioning to keep two lines from overlapping on screen, removing that positioning can put both lines in the same spot. Worth a quick check after converting.
Is the timing exactly preserved?
Yes — only the timestamp format changes (ASS centiseconds to WebVTT's HH:MM:SS.mmm), never the actual start/end times.
Is there an API for this?
Yes — see the API reference for the ass-to-vtt endpoint and curl examples.
More converters

Related tools and guides

ASS/SSA (Advanced SubStation Alpha) → SRT (SubRip)

Turn a styled .ass or .ssa subtitle into plain SubRip — dialogue and exact timing kept, fonts, colors, positioning and karaoke stripped since SRT can't hold them.

SRT (SubRip) → WebVTT

Turn a plain .srt file into WebVTT for HTML5 video, YouTube uploads or any platform that expects .vtt captions.

WebVTT → SRT (SubRip)

Turn a .vtt caption file into plain SubRip for players and editors that expect .srt — timing preserved exactly.

How to convert ASS/SSA subtitles to SRT

Convert Advanced SubStation Alpha (.ass/.ssa) subtitles to plain SRT for TVs, Plex and players that don't support styling — offline, with timing preserved exactly.

Anime subtitles: formats, sync, translation and cleanup, explained

Anime subtitles come with problems regular subtitles don't: ASS styling, fansub encoding issues, release-to-release timing drift. Here's how to fix each one, offline.