SAMI File Format (.smi)
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.
SAMI at a glance#
| Full name | Synchronized Accessible Media Interchange |
|---|---|
| File extension | .smi |
| Category | Subtitles |
| Developer | Microsoft |
| First released | 1998 |
| Other extensions | .sami |
| Compression | Uncompressed |
| FileFlip support | FileFlip reads this format but does not write it |
What a .smi file can hold#
These are the things a SAMI file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Selectable text | Yes |
|---|---|
| Human readable | Yes |
Strengths and limitations of SAMI#
What SAMI does well
- Windows Media Player picks it up automatically when a .smi file shares a video's filename in the same folder
- CSS-style classes let one file hold captions for multiple languages, switched by class rather than by separate files
- Plain markup that's readable and editable in any text editor
Where SAMI falls short
- Tied to the Windows Media era and rarely produced by current captioning tools
- Its HTML/CSS-subset markup is looser than a real HTML or XML spec, so parsers vary in what they accept
- No positioning beyond what its limited CSS subset can express
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.
How to open a .smi file#
A .smi file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts SAMI into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | Windows Media Player, VLC, Subtitle Edit |
| macOS | VLC |
| Linux | VLC |
| Web | FileFlip |
SAMI 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.
Converting SAMI files#
Convert SAMI to another format
FileFlip does not write .smi files, so nothing on the site converts into this format. It works as a source only.
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.