Convert ASS / SSA to TTML
Drop in a ASS / SSA file and get clean, valid TTML back in milliseconds. Runs entirely in your browser — your file never uploads.
Input
ASS / SSA file
Subtitle file
Output
TTML file
Spec-compliant
- Runs 100% in your browser — nothing uploads
- No file size limits
See it in action
ASS / SSA in, TTML out
What you put in → what you get back
ASS / SSA input
What you provide
[Script Info] ScriptType: v4.00+ [V4+ Styles] Format: Name, Fontname, Fontsize, … Style: Default,Arial,24,&H00FFFFFF,… [Events] Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text Dialogue: 0,0:00:12.34,0:00:15.78,Default,,0,0,0,,Hello, it's me Dialogue: 0,0:00:15.78,0:00:19.20,Default,,0,0,0,,I was wondering if after all
TTML output
What you receive
<?xml version="1.0" encoding="UTF-8"?>
<tt xmlns="http://www.w3.org/ns/ttml">
<body>
<div>
<p begin="00:00:12.340" end="00:00:15.780">Hello, it's me</p>
<p begin="00:00:15.780" end="00:00:19.200">I was wondering if after all</p>
<p begin="00:00:19.200" end="00:00:22.840">these years you'd like to meet</p>
</div>
</body>
</tt>Step-by-step guide
How to use this tool
- 01
Paste or drop ASS / SSA
Any valid ASS / SSA file works — paste the text or drag the file in.
- 02
Hit Convert
We parse the ASS / SSA structure and emit valid TTML.
- 03
Verify the output
Compare side-by-side. Use the Switch Direction button to round-trip and sanity-check.
- 04
Download TTML
Filename auto-suffixed with .ttml so it's ready to drop into your editor.
Key features
Why use this tool
100% in your browser
We never see your file. Conversion runs as JavaScript in the page you're reading.
Round-trip safe
Convert ASS / SSA → TTML → ASS / SSA and you should get the same content back, line-for-line.
Spec-compliant output
TTML files validate against the TTML reference parsers.
Bidirectional
Reverse direction (TTML → ASS / SSA) is one click away — no need to bookmark a different page.
Common use cases
Who this tool is for
From ASS / SSA
Aegisub, MPC-HC, MPV with libass, OBS Studio.
To TTML
Apple Netflix, BBC iPlayer, EBU-TT pipelines.
Localization workflows
Translate once in your preferred format, ship to every platform.
Format mismatch fixes
Got a file in the wrong format? Convert in seconds, no editor required.
Questions answered
Frequently asked questions
Need to go the other way?
TTML → ASS / SSA works the same way — we even have a button to switch direction.