ASS to VTT Converter – Free & No Upload

Quick answer

To convert ASS to VTT you strip the styling and produce web-ready captions. This tool reads each `Dialogue:` line, adds the required `WEBVTT` header, converts centisecond times to millisecond WebVTT timestamps, turns `\N` into line breaks, and removes ASS styles, positioning and override tags. It runs in your browser and hands back a .vtt for the HTML5 `<track>` element — nothing is uploaded.

How to ass to vtt converter

Load your ASS file
Drag an .ass or .ssa file in, or paste the script. The styles and events are parsed automatically.
Convert to WebVTT
The tool writes a WEBVTT header, extracts dialogue, converts timestamps to the period form, and drops styling and positioning.
Save the VTT
Download the .vtt file and reference it from a `<track>` tag inside your HTML5 `<video>`.

Why does web video need VTT rather than ASS?

The HTML5 <track> element that puts captions on a <video> in a browser accepts only WebVTT. It cannot read ASS at all — no player built into a browser understands the SubStation format. So however beautifully typeset your .ass is, to caption a web page you must first convert it to VTT. This is the trade-off: you gain browser compatibility and lose the styling the browser could never have rendered anyway.

What survives and what is dropped?

Text and timing survive; the entire ASS styling layer does not, because WebVTT captions are styled with CSS on the page, not with instructions baked into the file:

From ASS to WebVTT.
ASS element	In the VTT?
Dialogue text	Kept
Start / end timing	Kept (converted to milliseconds)
`\N` line breaks	Kept (become real breaks)
`WEBVTT` header	Added (required)
Fonts, colours, outlines	Dropped
`\pos` and positioning	Dropped
Karaoke, fades, effects	Dropped

Using the file in a page

Point a <track> at the converted file inside your <video>:

<video controls>
  <source src="movie.mp4" type="video/mp4" />
  <track kind="subtitles" src="movie.vtt" srclang="en" label="English" default />
</video>

Is the ASS file uploaded?

No. The script is parsed and the WebVTT is generated locally in your browser, with no network request. Check the Network tab in DevTools while you convert — nothing is sent. Your captions stay on your device.

Prefer SubRip for desktop players? Use ASS to SRT. If you started from a plain SRT, SRT to VTT is the direct route. Every other pair is handled by the universal subtitle converter, and to clear out stray tags first there is remove formatting. When you would rather bake the captions in than rely on a track, add subtitles to a video.

Your files never leave your device

Processed locally in your browser — nothing is uploaded. You can verify it yourself: open your browser’s developer tools, watch the Network tab, and use the tool — no upload request is ever made.

Frequently asked questions

Why won’t my ASS captions play on my website?

The HTML5 `<track>` element only reads WebVTT and cannot parse ASS at all. Convert the .ass to .vtt first and reference the .vtt from the track tag.

Does ASS to VTT lose the styling?

Yes. ASS fonts, colours, outlines and positioning are dropped because WebVTT does not store styling in the file. You restyle on the page with `::cue` CSS instead.

Is the timing preserved?

Yes. Centisecond ASS timestamps are converted exactly to millisecond WebVTT timestamps, so cue timing matches the original.

Does the tool add the WEBVTT header?

Yes, always. A WebVTT file must begin with the literal word WEBVTT on its first line or browsers reject it, so the converter adds it automatically.

Can I keep colour on the web captions?

Not from the file. Add colour with a `::cue` CSS rule on your page, which is how WebVTT captions are styled in the browser.

What MIME type should the .vtt use?

text/vtt. A wrong content type such as text/plain is the usual reason correctly linked captions fail to appear.

Do line breaks survive?

Yes. `\N` breaks in the ASS dialogue become real line breaks in the WebVTT cue, so multi-line captions keep their shape.