Why is my converted TTML file larger than the original SUB?

File size depends on compression settings and content complexity. Try the Medium quality preset for smaller output, or the file may simply contain data that resists TTML compression.

What browsers are supported?

Chrome, Firefox, Safari and Edge (all recent versions). Any browser supporting WebAssembly will work.

Is there a watermark on converted TTML files?

No. Free conversions produce clean output with no watermarks. Your TTML file is identical to what a paid desktop tool would produce.

Will this converter work on Chromebook?

Yes! Chromebooks run Chrome browser, which fully supports Xonvert's WebAssembly-based conversion engine.

Will I lose quality converting SUB to TTML?

No — TTML preserves quality losslessly. Your output will be faithful to the original.

Does this tool support drag and drop?

Absolutely. Drag files directly from your file manager onto the converter area. You can also click to browse, or paste from clipboard.

Can I adjust conversion quality settings?

Yes. The settings panel lets you control output quality, resolution and format-specific parameters. Default settings are optimized for best results.

Convert SUB to TTML

Fast, free, and secure SUB to TTML conversion. No registration required.

sub

Subtitle

ttml

Fast, free, and secure SUB to TTML conversion. No registration required.

Drag & drop your file here

or click to browse

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High Quality

Maintain maximum quality during conversion

Fast Processing

Convert files in seconds with our optimized engine

Secure & Private

Files automatically deleted after conversion

How to Convert SUB to TTML

Upload SUB File

Click the "Select File" button to upload your sub file from your device.

Start Conversion

Click the "Convert" button to instantly start converting to TTML.

Download TTML

Download your converted ttml file immediately after processing.

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