Convert IMSC
to SMI
Drop in a .xml (Internet Media Subtitles and Captions) 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 IMSC to SMI?+
Internet Media Subtitles and Captions is the modern W3C streaming profile of TTML used by Netflix, Apple TV, and most streaming services. 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?+
Neither format carries styling, so there's nothing to lose. The text and timing transfer exactly.
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.