Convert SMI
to VTT
Drop in a .smi (SAMI (Synchronized Accessible Media Interchange)) file, get a clean .vtt (WebVTT) back. WebVTT is the W3C web standard for HTML5 <track> captions, with cue settings and basic styling. The conversion runs entirely in your browser — your captions never leave the page.
Frequently asked
Why convert SMI to VTT?+
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. WebVTT is built for captions on the web via HTML5 <track>. 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 VTT 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.