Convert VTT
to SMI
Drop in a .vtt (WebVTT) file, get a clean .smi (SAMI (Synchronized Accessible Media Interchange)) back. 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. The conversion runs entirely in your browser — your captions never leave the page.
Frequently asked
Why convert VTT to SMI?+
WebVTT is the W3C web standard for HTML5 <track> captions, with cue settings and basic styling. SAMI (Synchronized Accessible Media Interchange) is built for legacy Windows Media workflows and certain Asian broadcast deliverables. 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?+
Most styling drops in this direction. VTT supports inline styling and SMI doesn't, so override codes, cue tags, and positioning attributes are stripped. Timing and text always survive.
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.