Add your SAMI file
Drop one or more .sami files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Converting a .sami file to .vtt extracts the document's content from its office package into a portable form. Free, private, and validated — the file never leaves your browser.
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.Converting a .sami file to .vtt extracts the document's content from its office package into a portable form. A .sami file is the same Synchronized Accessible Media Interchange caption document as .smi, written with the long form of the extension. The contents are identical — <SYNC Start=…> elements inside an HTML-like SAMI document — and the long extension is chosen mainly to avoid colliding with SMIL files, which also claim .smi.
A .vtt file is a WebVTT caption document: a WEBVTT header followed by timed cues for HTML5 video and audio. It is the web-native caption format browsers expect for the track element. For this route the practical draw is first-class support in modern browsers and richer cue settings than SubRip — balanced against some legacy desktop players prefer .srt and mishandle WebVTT settings, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .sami, some players recognise only .smi and must be given a renamed copy. Switching to .vtt buys you first-class support in modern browsers, which is why it is the better fit for captioning HTML5 video with the track element. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | SAMI captions (.sami) | WebVTT subtitles (.vtt) |
|---|---|---|
| Format type | Text-based — characters and structure, so there is no visual quality loss | Text-based — characters and structure, so there is no visual quality loss |
| How it stores data | byte for byte the same format as .smi: <SAMI>, <HEAD> with a <STYLE> block, and <BODY> with SYNC elements | files begin with WEBVTT and optional metadata headers before the first blank line |
| Strongest at | storing SAMI captions where .smi would collide with SMIL files | captioning HTML5 video with the track element |
| Weak spot | some players recognise only .smi and must be given a renamed copy | some legacy desktop players prefer .srt and mishandle WebVTT settings |
Drop one or more .sami files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .vtt in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if VTT is selectable, the route is real and validated.
Press Convert. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid VTT file. Outputs keep the original filename with the .vtt extension.
There is no visual quality to lose — sami is text-oriented and vtt is text-oriented, so the question is structural fidelity. Text, ordering, and basic structure are preserved; complex layout, embedded objects, and styling beyond the target's model are simplified.
Yes — the .sami file is processed inside your browser tab and never uploaded. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded. Close the tab and the file is gone from memory.
Chrome, Firefox, Safari, and Edge render .vtt through HTML track elements. Professional editors and many downloadable players also import it, though SubRip remains more common in older desktop workflows.
It depends on the content: files begin with WEBVTT and optional metadata headers before the first blank line. Convert one representative file first and compare before batch-processing a large set.
In .sami, as with .smi, the style block and language classes describe presentation; only cue timing and text are carried into other formats. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .sami → .vtt → .sami is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.