Convert SRT to ASS

How to convert SRT to ASS

1. Open your .srt file

   Drop one SubRip file into the box above, or click to browse. It’s read by your browser and never uploaded.

2. Check the result

   The “What changes” list says what the ASS file gains and loses, and the preview shows the SubRip text before and the ASS script after.

3. Download the .ass file

   Save the converted file. It keeps the original name with the new extension, so episode-01.srt becomes episode-01.ass.

Why people turn SRT into ASS

SubRip is the most widely read subtitle format because it is so plain: a number, a start and end time, and the words. That plainness is also its limit. An .srt file says nothing about how the text should look, so a TV, a phone and VLC each draw it their own way, in their own font and size.

Styling. Advanced SubStation Alpha was made for the opposite job. The file carries a table of named styles, each with a font, a size, four colours, an outline, a shadow and margins, and every line points at one of them. Fan translators, anime groups and video editors use it to give subtitles a consistent look, or a second style for signs and songs.

Burning subtitles in. Tools that print subtitles into the picture, such as HandBrake, FFmpeg with libass, or many video editors, follow the ASS style exactly. Starting from an .ass file means the burned-in text has the font and outline you chose instead of a default.

Editing in Aegisub. Aegisub opens SRT too, but it converts on the way in. Doing the conversion here first gives you a file with a sensible 1080p style that you can adjust once rather than line by line.

What the conversion does

Writes a script header. The file starts with [Script Info], which declares a 1920 × 1080 canvas, and [V4+ Styles] with one style named Default: white Arial at size 64, a black outline and a soft shadow, centred at the bottom with comfortable margins. Every line uses that style, so you only change it in one place.

Turns each block into a Dialogue line. The cue numbers are dropped, since ASS doesn’t use them. Times are rewritten as 0:01:02.35: ASS counts hundredths of a second, so each SubRip time is rounded to the nearest one.

Keeps simple formatting. <i>, <b> and <u> become {\i1}, {\b1} and {\u1}. A line that already starts with {\an8}, as many SDH and forced subtitles do, stays at the top of the screen. Line breaks become \N, the hard break ASS players respect.

Removes the rest, and counts it. A <font color> tag has no direct place in an ASS line, so it is removed and counted. The notice above the Download button gives the total, so nothing disappears silently.

Puts lines in time order. Some SRT files list lines out of order after hand editing. The ASS file lists them by start time.

Tips

Change the look in the style, not the lines. In Aegisub, open Subtitle → Styles Manager and edit Default. A bigger font or a yellow colour applies to every line at once.

Keep the .srt as well. Many TVs and phones don’t read ASS at all. Keep the original for those, and use the .ass for players with a renderer such as VLC, mpv, MPC-HC or Plex with burn-in.

Have WebVTT captions instead? Convert VTT to ASS does the same for .vtt files and keeps cue positions as {\an8} codes.

Subtitles out of sync too? Converting never moves a line. If the subtitles come early or late against your video, fix them with Shift Subtitle Timing before or after converting. If letters look garbled in the preview, pick another encoding next to the file name, or use Fix Subtitle Encoding.