CAB to Z Converter
FileFlip converts CAB to Z entirely inside your browser, using libarchive 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 CAB file to Z?#
- Drop your CAB 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 Z and the conversion starts on its own. FileFlip downloads 1.0 MB of WebAssembly the first time and nothing after that, then runs libarchive on your own machine.
- Save the Z file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting CAB to Z lose quality?#
No. Converting CAB to Z does not touch the files inside the archive. Each member is read out and written back byte for byte, so only the wrapper around them changes and nothing is recompressed.
Is it safe to convert CAB files online?#
Yes, because nothing is uploaded. FileFlip converts CAB 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 CAB to Z actually does to the file#
Converting CAB to Z runs on libarchive, downloads 1.0 MB of WebAssembly the first time and nothing after that, copies the archived files through unchanged, keeps file contents.
| Engine | libarchive |
|---|---|
| Conversion path | 2 steps: CAB → the unpacked files → Z |
| Downloaded to your browser | 1.0 MB, once, then cached by your browser |
| Quality | Lossless, contents copied unchanged |
| 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 |
|---|---|---|
| File contents | Kept | Carried through into the converted file. |
| File timestamps | Sometimes | Survives for some files and not others. |
| File permissions | Sometimes | Survives for some files and not others. |
Worth knowing before you start:
- the output is a PAX tar archive inside the compressor, not a single compressed stream
- every entry is extracted into memory before anything is written, so a very large archive can exhaust it
What is a CAB file?#
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 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.
What is a Z file?#
A Z file is a single stream compressed with the LZW algorithm by the Unix compress utility, the format gzip was written specifically to replace once a patent on LZW made distributing compress a legal risk.
There's essentially no reason to create a new Z file today; gzip replaced it decades ago with better compression and no patent risk.
Convert an old Z file to GZ or XZ so modern tools that dropped compress support can actually open it.
CAB to Z questions people ask#
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.
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.
Is a .Z file the same as gzip?
No. A .Z file is compressed with the older Unix compress utility's LZW algorithm, not gzip's DEFLATE, and the two aren't interchangeable; a tool built to read .gz files can't decompress a .Z file.