Extract CAB Files Online — Open Windows Cabinet Archives Free
Cabinet (.cab) is a Microsoft archive format used extensively in Windows for storing system files, device drivers, Windows Update packages, and software installers. You'll encounter .cab files when installing hardware drivers (they often arrive in a folder full of .inf and .cab files), when inspecting Windows Update downloads (.msu and .msp files contain CAB archives internally), or when dealing with legacy Windows software packages.
FastZip extracts CAB files entirely in your browser — no Windows required, no expand.exe, and no admin rights needed.
When you'll encounter CAB files:
- Device drivers — Most Windows hardware drivers are distributed as either an installer executable that unpacks to a CAB, or as a direct .cab file containing .inf, .sys, and .dll files. If you need to grab a specific .inf file for manual driver installation or to inspect driver contents, FastZip makes this easy.
- Windows Update packages — .msu (Microsoft Update Standalone) and .cab files are used for Windows patches. Security researchers and system administrators sometimes need to inspect the files inside a patch before deploying it.
- Legacy software — Many Windows applications from the 1990s and 2000s used Cabinet archives for their installation media. If you're archiving or inspecting old software, FastZip helps you see what's inside.
- Office and system components — Some Microsoft Office components and Windows system tools are distributed as CAB files that expand on installation.
CAB compression — Cabinet files use either no compression, MSZIP (a variant of ZIP's DEFLATE), or LZX compression (Microsoft's enhanced LZ algorithm, similar to but not compatible with LZMA). FastZip handles all three through its libarchive WebAssembly engine.
Format & Feature Reference
| CAB Property | Details |
|---|---|
| Compression options | None, MSZIP (DEFLATE), LZX |
| Max cabinet size | No hard limit |
| Multi-cabinet sets | Yes (sequential cabinets) |
| Digital signatures | Supported (not verified by FastZip) |
| Encryption | Not natively supported |
| Max file size free tier | 200 MB |
| macOS native support | No |
| Linux native support | cabextract tool only |
Extracting Device Drivers from CAB Files on macOS
macOS and Linux have no built-in CAB extraction tools. If you're a developer or IT administrator who needs to inspect Windows driver files from a Mac — to check version numbers, review .inf configuration, or copy specific DLLs — FastZip is the easiest solution.
Drop the .cab file into FastZip in Safari or Chrome. You'll see the complete file listing: .inf configuration files, .sys kernel drivers, .dll support libraries, and .cat signature catalogs. Download whichever files you need.
Multi-Cabinet (Multi-Disc) Archives
Large software distributions sometimes span multiple CAB files in a sequence (cabinet1.cab, cabinet2.cab, etc.). Each CAB file contains part of the data, and the full archive is only complete when all parts are present.
FastZip can open individual CAB files in the sequence. Extracting across multi-cabinet sets is a planned Pro feature. For single CAB files (which is most driver and patch scenarios), FastZip works perfectly.