SSA File Format (.ssa)
An SSA file is a SubStation Alpha v4 script split into a Script Info section, a Styles section defining named formatting templates, and an Events section holding every line of dialogue with its timing, style reference and positioning, the same three-section layout ASS later extended.
SSA at a glance#
| Full name | SubStation Alpha |
|---|---|
| File extension | .ssa |
| Category | Subtitles |
| MIME types | text/x-ssa |
| Compression | Uncompressed |
| FileFlip support | FileFlip reads and writes this format |
What a .ssa file can hold#
These are the things a SSA 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 SSA#
What SSA does well
- Named styles apply font, size, color and positioning to many lines from one definition
- Holds basic karaoke timing and positioning that plain-text formats like SRT can't carry
- Still opens in every editor and renderer that supports ASS, since ASS is a superset of it
Where SSA falls short
- Superseded by ASS (SubStation Alpha v4+), which added an alpha channel for transparency and more override tags
- Colors have no alpha channel, so semi-transparent text or outlines aren't possible
- Almost none of its styling or positioning survives conversion to SRT or other plain formats
Use SSA only when working with an existing v4 script or a tool that hasn't moved to ASS; a new styled subtitle is better authored directly in ASS.
Convert SSA to ASS to pick up transparency and the fuller set of override tags, or convert to SRT when the destination can't render styled subtitles at all and losing the styling is acceptable.
How to open a .ssa file#
A .ssa file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts SSA 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 | Aegisub, VLC, Subtitle Edit |
| macOS | Aegisub, VLC |
| Linux | Aegisub, VLC, mpv |
| iOS | VLC |
| Android | VLC, MX Player |
| Web | FileFlip |
SSA questions people ask#
Is SSA the same as ASS?
No, but they're the same lineage. SSA is SubStation Alpha version 4, and ASS (Advanced SubStation Alpha) is version 4+, an extension of the same three-section format that added an alpha channel for transparent colors, a numpad alignment system and karaoke tags SSA doesn't have.
Should I convert my SSA files to ASS?
It's worth it if you want transparency effects or the newer karaoke and override tags, since ASS is a strict superset of SSA and any renderer that plays ASS also plays SSA. If the file only uses basic styles and positioning, converting gains little.
What program opens an SSA file?
Aegisub is the standard editor for SSA and ASS scripts, and players like VLC and mpv render the styling and positioning directly. Because ASS renderers treat SSA as an earlier version of the same format, anything that opens .ass also opens .ssa.
Converting SSA files#
Convert SSA to another format
Convert another format to SSA
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.