VTT ⇄ ASS Converter
Convert WebVTT (.vtt) subtitles to Advanced SubStation Alpha (.ass), or ASS back to VTT. Supports files up to 200MB.
Or convert a file directly — supports files up to 200MB
Drag & drop a file here, or click to browse
Processed in the background, so the page stays responsive even for huge files
How to use this tool
Choose VTT → ASS or ASS → VTT, then paste or upload the file (.vtt, or .ass and .ssa). The output follows your edits, and Download saves it with the right extension. Uploads larger than 5 MB are converted by a background worker, to a maximum of 200 MB.
Worked example: web captions into ASS
WEBVTT NOTE checked 2026-09-26 intro 00:01.000 --> 00:03.000 line:0 <v Asha>Where were you?</v> 00:02.505 --> 00:04.000 <c.yellow><i>At home</i></c> <00:00:03.000>I swear
Dialogue: 0,0:00:01.00,0:00:03.00,Default,,0,0,0,,Asha: Where were you?
Dialogue: 0,0:00:02.50,0:00:04.00,Default,,0,0,0,,{\i1}At home{\i0} I swear- The speaker from
<v Asha>goes into the text as "Asha: ", not into ASS's Name field, so it will be shown on screen. line:0is not translated, so the first line moves from the top of the picture to the bottom. Add{\an8}to the start of such lines to put them back.- The NOTE block, the cue name
intro, the yellow class and the karaoke time are dropped; the italics become{\i1}. - ASS keeps time in hundredths of a second, so 2.505 s is written as 0:00:02.50.
ASS → VTT for a web player
Browsers can't show ASS in a <video> element, which is the usual reason to go this way. Each Dialogue line becomes one cue, with \N turned into a line break and bold, italic and underline kept as <b>, <i> and <u>. Everything that made the ASS file look the way it did goes: fonts, colours, and positions, including {\an8} and {\pos(…)}, so every line appears at the bottom in the player's default style. Lines marked Comment are skipped, and the Name column is not carried over.
Frequently Asked Questions
Which players can show the ASS file this creates?
Desktop players that render ASS, such as VLC and mpv, and subtitle editors like Aegisub, which is where you would add the styling that is the reason for choosing ASS. A web page cannot use it in a <video> element; keep the VTT for that.
Is it better to go VTT → SRT → ASS?
No. The result is the same either way, because both routes keep the same things: timing, text, speaker prefixes and bold, italic and underline. The one difference with SRT in the middle is an extra file to keep track of.
What if the ASS file uses a style other than Default?
ASS → VTT ignores style names, so lines on a "Signs" or "Songs" style come through as plain cues like any other. VTT → ASS always writes a single Default style; if you need separate styles for songs or signs, create them in Aegisub and assign them to those lines afterwards.
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