SAMI to TTML Converter
FileFlip converts SAMI to TTML entirely inside your browser, using FFmpeg compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert a SAMI file to TTML?#
- Drop your SAMI file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to TTML and the conversion starts on its own. FileFlip downloads 30.8 MB of WebAssembly the first time and nothing after that, then runs FFmpeg on your own machine.
- Save the TTML file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting SAMI to TTML lose quality?#
No. Subtitle cues are text, and converting SAMI to TTML rewrites the same timings and the same lines in the target's syntax. Anything TTML has no syntax for, such as positioning or styling, is dropped rather than degraded.
Is it safe to convert SAMI files online?#
Yes, because nothing is uploaded. FileFlip converts SAMI files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What SAMI to TTML actually does to the file#
Converting SAMI to TTML runs on FFmpeg, downloads 30.8 MB of WebAssembly the first time and nothing after that, rewrites the cues as text in the target's syntax, keeps cue durations.
| Engine | FFmpeg |
|---|---|
| Conversion path | One step: SAMI → TTML |
| Downloaded to your browser | 30.8 MB, once, then cached by your browser |
| Quality | Text preserved, unsupported styling dropped |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Cue durations | Kept | Carried through into the converted file. |
What is a SAMI file?#
A SAMI file is an HTML-flavored caption script built from <SYNC Start=milliseconds> blocks, each holding the caption text for one moment in the media, with CSS-style classes used to hold more than one language's captions in the same file.
Recognize SAMI as a legacy Windows Media caption file if it turns up alongside older video content; there's little reason to author new captions in it today.
Convert SAMI to SRT or VTT to caption video outside the Windows Media Player ecosystem, where SAMI support is inconsistent.
What is a TTML file?#
A TTML file is an XML document that marks up timed text with a <body> of styled, positioned regions and a series of <p> elements carrying start and end times, built to move captions between broadcast and streaming systems without losing formatting.
Use TTML when delivering captions into a broadcast or streaming pipeline that expects it, such as Netflix's or the EBU's ingest specifications.
Convert TTML to SRT or VTT when the destination is a general video player rather than a broadcast or streaming delivery system, since those rarely parse TTML directly.
SAMI to TTML questions people ask#
What is a SAMI (.smi) file?
A SAMI file is Microsoft's caption format from the Windows Media era, marking up timed captions with HTML-like <SYNC> tags in a file that Windows Media Player loads automatically when it shares a video's filename. The name stands for Synchronized Accessible Media Interchange.
Why does my SAMI file show captions in the wrong language?
A SAMI file can hold more than one language's captions in the same file, each under its own CSS-style class, and the player decides which class to display. If the wrong language shows, the player is choosing a different class than the one intended, not that the file is broken.
Does Windows Media Player play SMI files automatically?
Yes. Windows Media Player looks for a .smi file with the same name as the video file in the same folder and loads its captions automatically, without the file needing to be selected manually.
What is a TTML file used for?
A TTML file carries styled, timed captions through broadcast and streaming delivery pipelines, the way Netflix, the EBU and other distributors specify for ingesting subtitles. It's built for interchange between systems, not for opening directly in a typical media player.