SRT to ASS Converter

What this does

ASS is the format that supports fonts, colours, positioning and karaoke — which is why fansub groups and staged releases use it. SubRip supports none of that, so converting SRT upwards gives you a file a player like mpv, VLC or Aegisub can restyle, rather than a file that is already correct.

How to use it

1. Paste your .srt content into the box, or drop the file onto it.
2. A complete ASS v4+ script is written: [Script Info], one Default style in [V4+ Styles], and one Dialogue: line per cue in [Events].
3. Copy the result or download it as an .ass file, then restyle it in Aegisub or your player of choice.

Why the generated file looks plain at first

A converter cannot invent styling. SRT records text and timing, nothing else. So the ASS that comes out has one style — Arial at 64px, white with a black outline, centred near the bottom — and every cue points at it. That is a working baseline, not a finished look. The point of converting is to get the cues into a format where styling is possible; the styling itself is a design decision you make afterwards.

Timing converts cleanly in this direction. SubRip writes 00:00:01,000 with milliseconds. ASS writes 0:00:01.00 with centiseconds, so milliseconds are divided by ten and rounded down. A cue at 00:00:04,205 becomes 0:00:04.20 — a five millisecond difference, well below a frame at any normal frame rate.

Inline tags become override blocks. <i> and <b> in the SRT are rewritten as {\i1} / {\i0} and {\b1} / {\b0}, and any other markup is stripped rather than left to confuse the parser. Line breaks inside a cue become \N, the ASS hard break.

The PlayRes is set to 1920×1080. ASS positioning and font sizes are relative to the resolution declared in [Script Info]. Matching that to your video's resolution keeps the styling proportional — if your source is 1280×720, change PlayResX and PlayResY before you start styling, otherwise every measurement you set will be scaled.

Worked example

1
00:00:01,000 --> 00:00:04,000
Hello there.

2
00:00:04,200 --> 00:00:07,000
<i>Music playing</i>

[Script Info]
ScriptType: v4.00+
WrapStyle: 0
PlayResX: 1920
PlayResY: 1080

[V4+ Styles]
Format: Name, Fontname, Fontsize, ...
Style: Default,Arial,64,&H00FFFFFF,...

[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.00,0:00:04.00,Default,,0,0,0,,Hello there.
Dialogue: 0,0:00:04.20,0:00:07.00,Default,,0,0,0,,{\i1}Music playing{\i0}

Milliseconds became centiseconds, became {\i1}, and the cues now sit in an [Events] block that a player can restyle.