Free tool

VTT to ASS Converter

Turn a VTT subtitle file into ASS (Advanced SubStation Alpha) — a styleable format for Aegisub, fansubs and karaoke. Timecodes preserved, right in your browser.

100% in your browser — your files never leave your device.

How to convert VTT to ASS

  1. Step 1

    Add your subtitles

    Paste your VTT content into the box, or upload the .vtt file.

  2. Step 2

    Convert to ASS

    Click Convert — you get a valid .ass file with a Default style, ready to restyle.

  3. Step 3

    Copy or download

    Copy the result or download your .ass file.

Example: VTTASS

Here's the same cues before and after conversion, so you know exactly what you'll get.

Input — VTT (.vtt)
WEBVTT

00:00:01.000 --> 00:00:03.500
Hello — welcome to the show.

00:00:04.000 --> 00:00:06.200
Today we have a special guest.
Output — ASS (.ass)
[Script Info]
; Generated by SubtitleFlow
ScriptType: v4.00+
WrapStyle: 0
ScaledBorderAndShadow: yes
PlayResX: 1920
PlayResY: 1080

[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,60,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,1,2,10,10,40,1

[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.00,0:00:03.50,Default,,0,0,0,,Hello — welcome to the show.
Dialogue: 0,0:00:04.00,0:00:06.20,Default,,0,0,0,,Today we have a special guest.

The formats explained

What is VTT? (WebVTT)

The W3C subtitle format required by HTML5 video and most web players. Like SRT but with a WEBVTT header and dot-separated milliseconds, plus optional styling and positioning cues.

What is ASS? (Advanced SubStation Alpha)

A styled subtitle format used by anime fansubbers and Aegisub. It supports fonts, colours, positioning and karaoke through override tags — far richer than SRT or VTT, but not universally supported.

Why convert VTT to ASS?

  • ASS (Advanced SubStation Alpha) supports styling, positioning and karaoke — the format anime fansubbers and Aegisub use.
  • Start from a plain SRT/VTT and get a styleable .ass to refine.
  • The output carries a Default style; open it in Aegisub to add fonts, colours and effects.

FAQ

How do I convert VTT to ASS?

Paste or upload your VTT file and click Convert. You get a valid Advanced SubStation Alpha (.ass) file with a Default style and your original timing, ready to style in Aegisub.

Will it add styling automatically?

It creates a clean .ass with a single Default style — the styling, positioning and karaoke are yours to add in an editor like Aegisub.

Are my files uploaded?

No. Conversion happens entirely in your browser; nothing is sent to a server.

Need to translate your subtitles too?

Converting is free here. When you need to translate subtitles into another language with the timeline kept perfectly aligned, that's what SubtitleFlow does.

Translate subtitles free

Related tools

VTT to ASS — Convert VTT to Advanced SubStation Alpha (Free) | SubtitleFlow