Convert TTML to VTT Online Free
Convert TTML broadcast and streaming subtitle files to WebVTT format for HTML5 video and web-based media players. ChangeThisFile extracts cues from TTML XML and outputs valid VTT.
By ChangeThisFile Team · Last updated: March 2026
ChangeThisFile converts TTML to VTT on a secure server. Upload your TTML XML subtitle file and it is converted to WebVTT with a proper WEBVTT header and period-separated timestamps. Files are auto-deleted after conversion. Free with no signup required.
Convert TTML to VTT
Drop your TTML file here to convert it instantly
Drag & drop your .ttml file here, or click to browse
Convert to VTT instantly
TTML vs VTT: Format Comparison
Key differences between the two formats
| Feature | TTML | VTT |
|---|---|---|
| Standard | W3C TTML XML | W3C WebVTT |
| Structure | XML document tree | Plain text cue blocks |
| Styling | XML attributes (tts:*) | CSS STYLE blocks |
| HTML5 support | Via polyfills only | Native <track> element |
| Positioning | Named TTML regions | Cue settings per line |
| File size | Large XML | Compact text |
| Primary use | Broadcast/professional | Web video players |
When to Convert
Common scenarios where this conversion is useful
Serving broadcast subtitles in an HTML5 video player
HTML5 video players use the <track> element which requires VTT. If you have TTML subtitle files from a broadcast source, converting to VTT enables immediate web playback.
Publishing streaming platform content on a website
When re-publishing content that originated from a TTML-based streaming platform on a website, converting to VTT makes the subtitles compatible with web video infrastructure.
Testing subtitle rendering in a browser
Browsers do not natively render TTML. Converting to VTT lets you test subtitle timing and content in any browser using the <track> element without additional libraries.
How to Convert TTML to VTT
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1
Upload your TTML file
Drag and drop your TTML subtitle file onto the converter, or click browse. The upload is encrypted.
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2
Server-side conversion
The server parses the TTML XML, extracts <p> cues with begin and end times, converts timestamps to VTT's period-millisecond format, and adds the WEBVTT header.
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3
Download the VTT
Save your converted WebVTT file. The server copy is automatically deleted after processing.
Frequently Asked Questions
VTT is better suited for web video since it supports CSS styling, cue positioning, and native HTML5 integration. SRT is simpler but lacks web-native features. Choose VTT if you are targeting a web video player.
Basic TTML styling attributes are not automatically mapped to VTT CSS. The VTT output contains the cue text as plain text. You can add VTT STYLE blocks manually after conversion.
Multi-region TTML files are supported. Region placement is discarded in the VTT output since VTT uses a different positioning model.
Yes. The converted VTT is W3C-compliant and can be used directly: <track kind="subtitles" src="subtitles.vtt" srclang="en">.
The converter handles standard HH:MM:SS.mmm timestamps and frame-based HH:MM:SS:ff timecodes commonly used in broadcast TTML files.
Yes. Files are transferred over HTTPS and deleted automatically after your VTT is ready.
TTML files can be larger due to XML overhead. The 50 MB server limit accommodates virtually any subtitle file.
The converter extracts text from <span> child elements within <p> elements. Nested span text is concatenated with spaces into a single cue.
Yes. ChangeThisFile supports VTT to TTML conversion for round-trip workflows.
DFXP (Distribution Format Exchange Profile) is an earlier version of TTML. They share the same XML structure. ChangeThisFile also supports DFXP to SRT and SRT to DFXP conversion.
Related Conversions
Need to convert programmatically?
Use the ChangeThisFile API to convert TTML to VTT in your app. No rate limits, up to 500MB files, simple REST endpoint.
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