PST

VTT to ASS Converter

Upload a WebVTT (.vtt) subtitle file and instantly download it as an Advanced SubStation Alpha (.ass) file. Timestamps are converted to centisecond precision and a default style sheet is included.

Upload VTT File
Supported: .vtt (UTF-8). Drag and drop or choose a file.
Upload a VTT file to preview subtitle cues and download as ASS.

Fast, Private VTT to ASS Conversion

Upload your WebVTT file and get a ready-to-use ASS file in seconds. No account needed. No file uploads. Everything runs in your browser.

Instant Conversion

Convert VTT to ASS in milliseconds - entirely in your browser. No server uploads, no queues, and no account required.

Default Style Sheet

The generated ASS file includes a complete [Script Info] and [V4+ Styles] section with sensible defaults, so it works immediately in VLC, mpv, and other ASS-capable players.

Accurate Timestamps

All start and end times are converted precisely from VTT millisecond format (HH:MM:SS.mmm) to ASS centisecond format (H:MM:SS.cc). No drift, no rounding errors.

One-Click Download

Preview all subtitle cues after uploading, then download the converted ASS file with a single click. Free, with no account required.

How to Convert VTT to ASS

  1. 1

    Upload your VTT file

    Drag and drop your WebVTT file onto the upload area, or click to open the file browser.

  2. 2

    Preview the subtitle cues

    The tool immediately parses your VTT file and shows all subtitle cues with their timestamps in the preview panel.

  3. 3

    Download the ASS file

    Click "Download ASS" to save the converted file. Timestamps are reformatted to centisecond precision and a default style sheet is included.

VTT to ASS examples, styling workflow, and format limitations

VTT to ASS gives you a valid ASS file from simple web captions so you can style the subtitles later in Aegisub or play them in ASS-capable desktop players.

Example input and output

VTT input
WEBVTT 00:00:02.400 --> 00:00:05.100 Welcome back.
ASS output
Dialogue: 0,0:00:02.40,0:00:05.10,Default,,0,0,0,,Welcome back.

Best for

Aegisub editing

Turn web captions into a file that can be styled, positioned, and typeset.

Desktop playback

Use ASS when you want outlines, shadows, or player-side style rendering.

Format handoff

Move captions from web workflows into subtitle production tools.

Common file issues handled

Default ASS sections

Script Info, Styles, and Events sections are generated automatically.

Cue identifiers

Optional VTT cue labels are not needed in ASS output and are skipped.

Positioning differences

VTT line and align settings do not map directly to ASS positioning.

Timing conversion

Millisecond VTT timing is converted to ASS centisecond timing.

Frequently Asked Questions

Why would I convert VTT to ASS?
ASS (Advanced SubStation Alpha) is the format of choice for anime fansubs and any use case requiring rich styling - custom fonts, colors, per-cue positioning, and animations. If you have a VTT file and want to add advanced styling in a tool like Aegisub, or play back with full ASS rendering in mpv or VLC, converting to ASS is the first step.
What does the generated ASS file contain?
The output is a complete, valid ASS file with three sections: [Script Info] (format metadata), [V4+ Styles] (a single Default style using Arial 20pt white text with a black outline), and [Events] (one Dialogue line per cue). You can open the file in Aegisub to customise the style sheet further.
Are VTT cue identifiers or positioning settings carried over?
No. VTT cue identifiers (the optional label before the timestamp) and positioning/alignment tags (e.g. align:start or line:10%) are not transferred to ASS, because ASS handles positioning through its own override system. Only the cue text and timing are converted.
Does this tool upload my file to a server?
No. The entire conversion happens locally in your browser using JavaScript. Your file never leaves your device, which keeps the conversion private after the page has loaded.
Which players support ASS subtitles?
Most desktop media players support ASS natively, including VLC, mpv, MPC-HC, and MPC-BE. Web browsers do not support ASS via the HTML5 <track> element - use VTT for web playback. For the best ASS rendering experience with full style support, mpv is recommended.