About CAB Files
Windows Cabinet
CAB (Cabinet) is a Windows archive format used for software installers.
Family
Archives & Compressed
Extension
.cab
MIME Type
application/vnd.ms-cab-compressed
Can Use As
43 41 42 46 00 01 00 00 4B 41 49 4A
ASCII: CABF....KAIJ
📈 Target Minimum File Size (Guaranteed ≥ KB)
Lossless JPEG Q100 + standard COM segment padding for government & exam portals
Tap to choose your file Drop files here or click to browse
Automatic format identification and lossless transcoding across 201+ formats.
Convert to:
Detecting available formats...
Target Max File Size:
Uploading...
Processing your file...
READY!
Download File
Your file is converted & verified! Unlock instant download:
One-time secure payment via Stripe (Apple Pay, Google Pay, Card). Zero recurring subscription.
🛡️ Verification Audit
- ✓
- ✓ sRGB Color Fidelity
- ✓
Continue with this converted file (0s zero re-upload):
Batch Conversion Ready!
Your file is converted & verified! Unlock instant download:
One-time secure payment via Stripe (Apple Pay, Google Pay, Card). Zero recurring subscription.
Need to convert larger files or bigger batches right now?
Unlock up to 1 GB & priority cloud queue with 1-click Stripe checkout (Apple Pay, Google Pay, Card):
HOW CAB CAME TO BE.
CAB — Microsoft Cabinet — shipped in 1994 with Windows 95 setup as the installation-archive format that replaced the DIZ/ARJ/ZIP patchwork of the DOS era. The format supports LZX compression (originally from Jonathan Forbes, licensed by Microsoft), MSZIP (a DEFLATE variant), and Quantum. A .cab file can span multiple disks — a design detail that mattered when Windows 95 shipped on 13 floppy disks.
CAB became the backbone of Windows installations for three decades. Every Windows Update, every .msi installer, every Office setup disk, every Service Pack: all built on CAB. Even today, many Windows system files are distributed as CAB archives, and the format is supported natively in Windows 10/11 via the `expand.exe` tool and Windows Explorer.
Technical Specifications
- MIME type
- application/vnd.ms-cab-compressed
- Extension
- .cab
- Compression
- MSZIP (DEFLATE), Quantum, LZX
- Max volume size
- 2 GB per file
- Multi-volume
- Yes (split archive spanning)
Typical Sizes & Weights
Single driver package
100 KB - 20 MB
Windows Update patch
1-500 MB
Service pack archive
200 MB - 2 GB
STRENGTHS & LIMITATIONS.
Strengths
- Multi-volume — designed for disk-spanning archives.
- Multiple compression algorithms in one format.
- Native Windows support for 30+ years.
- Authenticode signing integrates with Windows security stack.
- Microsoft-maintained tooling (MAKECAB, EXTRAC32, expand.exe).
Limitations
- Windows-only ecosystem — limited Mac/Linux tooling.
- Proprietary container with partial public documentation.
- Overtaken by MSI (which uses CAB internally) for new installers.
- Compression ratios lag modern formats (zstd, xz).
CURIOSITIES & TRIVIA.
Windows 95 shipped on 13 floppy disks — every one a CAB file segment of the installer.
The LZX compression inside CAB came from a program called LZX, originally for Amiga archives, which Microsoft licensed in the early 1990s.
Every Microsoft Office installer (MSI) is backed by CAB archives for the binary payload.
Windows Update delivers patches as CAB files — the Windows Update Agent downloads and extracts them silently.
The format can span disks: a single archive can be split across multiple .cab files with the same basename.
Specialized Utilities for .CAB Files
Compress Files to ZIP
Compress multiple files and folders into a single ZIP archive. Reduce total size for faster transfers and organized storage.
Compress Image to 50KB
Compress JPG, PNG, or WebP photos to strictly under 50 KB (50,000 bytes) for passport portals, university admissions, civil service forms, and KYC uploads without changing pixel dimensions.
Merge PDF
Combine multiple PDF files into a single document. Drag and drop to reorder pages before merging. No software installation required.
Compress PDF
Reduce PDF file size without visible quality loss. Choose from low, medium, or high compression levels. Ideal for email attachments and web uploads.
CONVERT FROM CAB
Common Use Cases
Windows installers, drivers
Related Formats
Popular comparisons
CAB vs 7Z
Differences, file size, and when to choose each format.
CAB vs TAR
Differences, file size, and when to choose each format.
CAB vs GZ
Differences, file size, and when to choose each format.
CAB vs BZ2
Differences, file size, and when to choose each format.
CAB vs XZ
Differences, file size, and when to choose each format.
CAB vs LZMA
Differences, file size, and when to choose each format.
Popular CAB conversions
The most-requested destinations when starting from CAB.
Frequently Asked Questions
CAB (Windows Cabinet) is an archive format used to bundle multiple files and folders into a single compressed file. The archive preserves the directory structure and typically reduces total size via compression. CAB sits in the archives & compressed family and has specific strengths around compression ratio, speed, or platform support.
7-Zip, WinRAR, The Unarchiver (macOS), and the built-in archive utilities on Windows and macOS open most CAB files. For command-line extraction, 7z, unar, or the format-specific tool handles CAB cleanly. If your extractor does not recognise CAB, convert to ZIP first — ZIP opens on every operating system without extra software.
Upload the CAB to KaijuConverter and pick ZIP, 7Z, TAR.GZ, or RAR as the target. Our pipeline extracts the original archive and re-compresses the contents into the target format. File permissions, timestamps, and directory structure are preserved where both formats support them.
Depends on the goal. ZIP is the universal baseline — every OS extracts it out of the box. Formats like 7Z or TAR.GZ compress better but require specific tools. CAB may win on compression ratio, password support, or OS integration for specific workflows; ZIP wins on raw compatibility.
Need to Convert Gigabyte Archives or Mass Folders?
KaijuConverter delivers ultra-fast in-memory conversions for everyday tasks. For multi-gigabyte production workloads without browser bandwidth bottlenecks, explore high-throughput desktop suites.
One-time payment with zero recurring commitment: convert files up to 1 GB, OCR, PDF/A, and .ZIP batches for 24 hours.
Full 7 days of unlimited conversions, up to 2 GB per file, 100% ad-free with zero subscription.
High-throughput enterprise pipeline for files up to 2,048 MB, 50-file batches, ISO PDF/A, and priority processing.
Convert thousands of camera RAW files (CR3, NEF, ARW) to WebP, AVIF, or TIFF in one pass.
GPU-accelerated RAW development with end-to-end 16-bit ICC color profile management.