CAB File Format (.cab)
A CAB file is Microsoft's cabinet archive, a single compressed container that Windows Setup, Windows Installer and driver packages use to hold the files they install.
CAB at a glance#
| Full name | Microsoft Cabinet |
|---|---|
| File extension | .cab |
| Category | Archives |
| Developer | Microsoft |
| MIME types | application/vnd.ms-cab-compressed |
| Compression | Lossless |
| Specification | Microsoft Cabinet Files |
| FileFlip support | FileFlip reads this format but does not write it |
What a .cab file can hold#
These are the things a CAB file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Lossless compression | Yes |
|---|---|
| Embedded metadata | Yes |
Strengths and limitations of CAB#
What CAB does well
- Compresses across file boundaries rather than per file, so a cabinet full of similar files beats naive per-file compression
- Supports spanning a large payload across multiple linked cabinet files, which is how older Windows installers fit onto floppy disks and later multiple CDs
- Windows extracts one natively with no extra software, since File Explorer and expand.exe both understand the format
Where CAB falls short
- Proprietary Microsoft format, so cross-platform support depends entirely on third-party reverse-engineered tools
- The classic LZX and Quantum compression methods it supports are specific to Windows tooling, unlike the general-purpose compressors other archive formats use
- Built for installing files onto a system rather than general-purpose archiving, so it lacks features like encryption that people expect from a modern archive tool
CAB is the format to reach for when building a Windows driver package or installer component, since Windows Setup and Windows Installer both expect it.
Convert a CAB archive to ZIP when its contents need to be handled on a system without Windows' built-in cabinet support.
How to open a .cab file#
A .cab file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts CAB 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 | File Explorer (built-in expand), 7-Zip, WinRAR |
| macOS | Keka, p7zip (command line) |
| Linux | cabextract, 7-Zip (p7zip) |
| Web | FileFlip |
CAB questions people ask#
What is a CAB file used for?
A CAB file is Microsoft's cabinet archive format, used to package the files inside Windows installers, Windows Update packages and printer or device driver bundles. Windows extracts one natively without any extra software.
How do I open a CAB file on Windows?
Right-clicking a CAB file in File Explorer and choosing Extract All unpacks it directly, since Windows has built-in cabinet support. The command-line expand.exe tool does the same thing for scripting.
Can I open a CAB file on macOS or Linux?
Yes. The cabextract command-line tool handles CAB files on Linux and macOS, and 7-Zip's Linux and macOS port, p7zip, reads them as well, since Microsoft's cabinet format has been reverse-engineered thoroughly enough that third-party tools support it reliably.
Converting CAB files#
Convert CAB to another format
FileFlip does not write .cab 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.