Convert SMI
to TTML
Drop in a .smi (SAMI (Synchronized Accessible Media Interchange)) file, get a clean .ttml (Timed Text Markup Language) back. Timed Text Markup Language is the W3C XML standard used by streaming platforms (Netflix, Disney+) and broadcast pipelines. The conversion runs entirely in your browser — your captions never leave the page.
Frequently asked
Why convert SMI to TTML?+
SAMI (Synchronized Accessible Media Interchange) is Microsoft's HTML-like caption format from Windows Media Player era. Still required by some Korean and Japanese broadcast pipelines. Timed Text Markup Language is built for delivery to streaming or OTT ingest. Converting lets you take a file produced for one workflow and use it in the other without re-typing or re-timing anything.
Is timing preserved exactly?+
Yes. The converter only re-encodes the file structure — start and end times round-trip to within one millisecond.
Does any styling survive the conversion?+
SMI doesn't carry styling, so the output TTML uses default formatting. Restyle in your editor after import.
Does this run on a server?+
No. The conversion is pure JavaScript running in your browser — files never upload anywhere. Works offline once the page is loaded.