TTML to ASS Converter
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100% local processing in your browser. No upload. No waiting. No limits.
Drag & drop your TTML file here
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Supports .ttml files up to any size
More Subtitle Tools
Why Choose AllSubConverter?
Your Privacy Matters
Everything runs in your browser. Your files are never uploaded.
Lightning Fast
Optimized processing engine converts files in seconds.
Truly Unlimited
No file size limits. No daily limits. Completely free.
Works Everywhere
Works on Windows, Mac, Linux, iOS, Android - any modern browser.
Free Online TTML to ASS Converter
Our TTML to ASS converter reads Timed Text Markup Language input and produces Advanced SubStation Alpha output entirely in your browser. Source TTML timing (seconds (1.500s) or clock values) is converted to ASS timing (H:MM:SS.cc centiseconds). Styling and markup that the target format cannot represent are normalized or stripped, leaving valid, ready-to-use output. The conversion runs client-side, so your subtitle files are never uploaded to a server.
Input Format
TTMLTTML (Timed Text Markup Language) is an XML-based subtitle format standardized by the W3C and required by Netflix, Apple TV, and many broadcast workflows. Captions live in <p> elements with begin and end (or dur) attributes that express time either as seconds (1.500s) or as clock values (HH:MM:SS.mmm). The related ITT (iTunes Timed Text) format shares the same XML structure and is handled the same way.
Output Format
ASSASS (Advanced SubStation Alpha v4+) is a styled subtitle format with [Script Info], [V4+ Styles], and [Events] sections. ASS supports per-character styling via override tags, fonts, colors, alpha transparency, outlines, shadows, blur, screen positioning, vector drawing, and karaoke timing. Timing uses centisecond precision (H:MM:SS.cc).
Features
Why Convert?
Format Differences
Common Use Cases
Styled Subtitles
Create ASS subtitles with fonts, colors, outlines, and positioning for visually rich presentation.
Anime & Karaoke
Produce ASS files for fansubbing and karaoke workflows that rely on override tags and libass rendering.
Aegisub Editing
Generate an ASS file you can open directly in Aegisub for further styling and timing work.
Related Formats
Frequently Asked Questions
It reads a Timed Text Markup Language file, parses each cue's timing and text, normalizes the structure for Advanced SubStation Alpha, and writes a valid .ass file. Source TTML timing (seconds (1.500s) or clock values) is converted to ASS timing (H:MM:SS.cc centiseconds).
Absolutely. Every conversion runs client-side in your browser. No subtitle data, file contents, or metadata is ever transmitted to a server.
TTML and ASS both support styling, but their styling models differ. Styling that cannot be mapped is normalized or dropped, while dialogue text and timing are always preserved.
Yes, completely free with no sign-up, no watermarks, and no file size limits. All processing happens in your browser, so your files are never uploaded to a server.
Source TTML timing (seconds (1.500s) or clock values) is converted to ASS timing (H:MM:SS.cc centiseconds).
Yes. The converter is fully responsive and works in any modern mobile browser on iOS and Android.