Add your SBV file
Drop one or more .sbv 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.
SBV to SMI
Converting a .sbv file to .smi extracts the document's content from its office package into a portable form. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop SBV files here
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.About converting YouTube SBV subtitles to SAMI captions
Converting a .sbv file to .smi extracts the document's content from its office package into a portable form. A .sbv file is a SubViewer-style caption document used by YouTube's caption editor: each cue is a single line of start,end timings followed by the caption text on the next lines, separated by a blank line. It carries the same timed dialogue as SubRip but divides the two timestamps with a comma instead of an arrow.
An .smi file is a SAMI caption document: HTML-like markup in which <SYNC Start=…> elements mark the millisecond at which a caption appears, and the caption runs until the next SYNC. Microsoft designed it as an accessibility format, so a single file can carry several languages selected by CSS class. For this route the practical draw is several language tracks in one file, chosen by class and plain text and editable anywhere — balanced against never formally standardised, so real-world files vary in structure, which is worth knowing before you commit a large batch.
Why convert SBV to SMI?
The practical trigger for this conversion is usually a mismatch: with .sbv, almost no desktop or browser player plays .sbv directly, so conversion is usually required. Switching to .smi buys you several language tracks in one file, chosen by class, which is why it is the better fit for captioning legacy Windows Media and Silverlight content. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
SBV vs SMI at a glance
| Aspect | YouTube SBV subtitles (.sbv) | SAMI captions (.smi) |
|---|---|---|
| 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 | each cue is a timing line H:MM:SS.mmm,H:MM:SS.mmm followed by one or more text lines and a blank separator | the document has an HTML shape: <SAMI> wrapping <HEAD> with a <STYLE> block and <BODY> with the SYNC elements |
| Strongest at | downloading and re-uploading captions through YouTube's caption editor | captioning legacy Windows Media and Silverlight content |
| Weak spot | almost no desktop or browser player plays .sbv directly, so conversion is usually required | never formally standardised, so real-world files vary in structure |
Pick SMI as the output
Select .smi in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if SMI is selectable, the route is real and validated.
Convert on your device
Press Convert. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid SMI file. Outputs keep the original filename with the .smi extension.
SBV to SMI questions, answered
Will converting SBV to SMI lose quality?
There is no visual quality to lose — sbv is text-oriented and smi 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.
Is it private to convert SBV files here?
Yes — the .sbv 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.
Where will the SMI file work?
Windows Media Player, VLC, PotPlayer, and MPC-HC read .smi, and Subtitle Edit converts it. Browsers do not. Novus Convert parses the SYNC blocks locally with document types and external entities refused and script and style content removed before any text is read, then writes any of the twelve timed-text targets.
Will the SMI file be bigger or smaller than my SBV?
It depends on the content: the document has an HTML shape: <SAMI> wrapping <HEAD> with a <STYLE> block and <BODY> with the SYNC elements. Convert one representative file first and compare before batch-processing a large set.
Can I convert SMI back to SBV?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .sbv → .smi → .sbv is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.