Free tool
SRT to ASS converter
Drop an .srt file here to convert SRT to ASS: pick a font, a size and top or bottom, and get an Advanced SubStation Alpha script with your captions as dialogue lines, ready to refine in Aegisub or burn into a video.
- Free
- No sign-up
- Nothing is uploaded
Nothing is uploaded: your browser reads the file.
Subtitling your own recordings? NoteOwl transcribes them on your Mac, unlimited, and saves SRT files that this page turns into styled ASS.
How it works
How do you convert SRT to ASS?
Open the .srt file and keep ASS selected. Type a font name, a size and whether captions sit at the bottom or the top. The converter writes the script header, one style and a dialogue line for each caption. Download the .ass file.
- 1
Open the SRT
Drop the file in, choose it, or paste the subtitles themselves.
- 2
Set the look
Font, size and position. The size is measured against a 1920 × 1080 picture, so 72 suits most videos.
- 3
Download the .ass
Load it in a player that reads ASS, open it in Aegisub, or burn it into the video.
What does an SRT file look like as an ASS script?
Three captions from a cooking video in SRT, and the ASS script this page writes with the default look: Arial at 72, at the bottom. The italic line uses ASS’s own tags, and the two-line caption is joined with \N.
1 00:00:01,000 --> 00:00:03,500 Salt the water well. It should taste like the sea. 2 00:00:04,000 --> 00:00:06,200 <i>Don't add oil to the pot.</i> 3 00:00:06,800 --> 00:00:09,900 Keep a cup of the cooking water for the sauce.
[Script Info]
Title: pasta-night
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,72,&H00FFFFFF,&H000000FF,&H00000000,&H80000000,0,0,0,0,100,100,0,0,1,3,1,2,60,60,50,1
[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,,Salt the water well. It should\Ntaste like the sea.
Dialogue: 0,0:00:04.00,0:00:06.20,Default,,0,0,0,,{\i1}Don't add oil to the pot.{\i0}
Dialogue: 0,0:00:06.80,0:00:09.90,Default,,0,0,0,,Keep a cup of the cooking water\Nfor the sauce.Why turn SRT subtitles into ASS?
To control how they look. SRT carries text and times only, and each player draws it its own way. ASS adds styles: the font, size, colours, outline, shadow and position, the same wherever an ASS-capable player shows it, or burned permanently into the picture.
What is inside the ASS file?
Three sections. Script Info sets a 1920 × 1080 canvas; V4+ Styles holds one style, Default, with your font, size and position; Events has a Dialogue line per caption with its start, end and text. All of it is plain text you can edit.
- Font and size
- ValueYours (Arial and 72 to start)
- Text colour
- ValueWhite, &H00FFFFFF
- Outline and shadow
- ValueBlack, 3 and 1 pixels wide
- Position
- ValueBottom centre (2) or top centre (8)
- Margins
- Value60 at the sides, 50 from the edge
- Times
- ValueTo the hundredth, as ASS stores them
| Setting | Value |
|---|---|
| Font and size | Yours (Arial and 72 to start) |
| Text colour | White, &H00FFFFFF |
| Outline and shadow | Black, 3 and 1 pixels wide |
| Position | Bottom centre (2) or top centre (8) |
| Margins | 60 at the sides, 50 from the edge |
| Times | To the hundredth, as ASS stores them |
How do you burn ASS subtitles into a video?
With FFmpeg’s subtitles filter, which draws ASS with the libass library: ffmpeg -i video.mp4 -vf subtitles=captions.ass output.mp4. The captions become part of the picture, so they show everywhere, including on sites that don’t take subtitle files.
Check the timing before you burn it in, because it can’t be changed afterwards. The subtitle shifter moves every line of an .ass file and leaves its styles alone.
Can you keep editing the file in Aegisub?
Yes. Aegisub, the free subtitle editor, opens the script as it is: change the Default style, add more styles for signs or songs, and position single lines. The speaker names from your SRT are already in each line’s Name field, where Aegisub calls them the actor.
Where do the SRT files come from in the first place?
From transcribing the video. NoteOwl imports a recording on your Mac, transcribes it with on-device AI models and saves an SRT file timed from the speech, with nothing uploaded; this page styles it. How NoteOwl makes SRT files.
FAQ
Questions about converting SRT to ASS
What font size should ASS subtitles use?
The converter writes a 1920 × 1080 canvas, so sizes are measured against a picture 1080 pixels tall: 60 to 80 reads comfortably on most videos, and 72 is the default. Players scale it to the video’s real size.
What if the font isn’t installed where the video plays?
The player falls back to another font it has, so the text still shows but looks different. Pick a common font such as Arial, or install yours on the computer that plays or burns the subtitles.
Why are the times rounded?
ASS stores times to the hundredth of a second, not the thousandth like SRT, so 00:00:01,234 becomes 0:00:01.23. A difference of a few milliseconds can’t be seen.
Are italics kept in the ASS file?
Yes. SRT’s italic, bold and underline tags become ASS override tags such as {\i1} and {\i0}, so those words keep their formatting.
Can I convert SRT to SSA instead?
The converter writes ASS, the newer version of SubStation Alpha (v4.00+). Editors and players that handle these scripts, including Aegisub and libass-based players, read ASS.
Is my SRT file uploaded?
No. The SRT to ASS converter runs in your browser; the script is written on your device and downloaded from there.
Keep exploring
More subtitle converters
- Subtitle converterConvert subtitles between SRT, VTT, SBV and ASS, or to plain text, in your browser; SSA scripts and meeting transcripts work too
- SRT to VTT converterConvert SRT to VTT, VTT to SRT, or either to clean text with each speaker’s lines merged, in your browser; Zoom and Teams transcripts work
- SRT to Word converterTurn an SRT subtitle file into a Word document in your browser: a table of captions with start and end times, or a clean transcript
- VTT to Word converterTurn a VTT file, such as a Teams or Zoom transcript, into a Word document in your browser: a transcript by speaker, or a table with times
- SCC to SRT converterConvert a Scenarist SCC (CEA-608) caption file to SRT, VTT or text in your browser: pop-on, roll-up and paint-on captions read frame by frame
Related
- Subtitle shifterMove every caption in an SRT, VTT, SBV or ASS file earlier or later, or re-sync it from two points; only the times change
- Subtitle generatorTurn a recording into an SRT subtitle file with timecodes and speaker names, on your Mac
- Online subtitle editorEdit an SRT or VTT file in your browser: change text and times, add and delete captions, catch overlaps and over-fast captions, download
Subtitles from your recordings, made on your Mac
Free to download. Runs entirely on your Mac.
macOS 26 or later · Apple Silicon (M1 or newer) · 16 GB memory minimum, 24 GB recommended
About NoteOwl
NoteOwl is private AI meeting notes and memory for the Mac. It captures meetings without a bot joining the call, labels every speaker, writes summaries and action items, and builds a memory of every conversation that you can chat with — fully offline, because the speech recognition and the AI run on the Mac itself. Dictation into any app is free; Pro is a one-time purchase.
NoteOwl pricing: what’s free and what Pro adds
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