cab

.cab — Cabinet File

Microsoft · 1997

Developer

Microsoft

Key Features

Compressed storage behavior for typical archive workflows
Common MIME type: application/vnd.ms-cab-compressed
Recognizable file signature: 4D 53 43 46
Associated with Microsoft

Best For

Packaging files for download
Backups and transfers
Reducing storage overhead

Less Ideal For

Direct viewing without extraction
Live editing inside the package
Formats requiring immediate preview

Common Use Cases

Bundling many files together
Reducing transfer size
Preserving directory structure during sharing

How to Open It

On Windows, open the file with Windows Explorer or 7-Zip.
On macOS, open the file with The Unarchiver or Keka.
If the file does not open, confirm that the extension really matches .cab and that the download or transfer completed without corruption.

What is a .cab file?

A CAB file is a compressed archive file format developed by Microsoft for storing multiple files in a single location. It is commonly used for distributing software updates, drivers, and system files on Windows operating systems. CAB files employ various compression algorithms to reduce file size, making them efficient for data storage and transfer.

Programs That Open .cab Files

Platform	Program
Windows	Windows Explorer	Free	Official
	7-Zip	Free
	WinRAR	Paid
	PeaZip	Free
macOS	The Unarchiver	Free
	Keka	Free
	Archive Utility	Free	Official

Common Problems with .cab Files

⚠️ File is corrupted or incomplete.

Re-download the file from the source or try to obtain it again. If the file is part of an installation, try re-downloading the installer.

⚠️ Cannot open the CAB file with a program.

Ensure you have a compatible archive utility installed. Try using a more common archiver like 7-Zip or WinRAR, or the built-in Windows extractor.

⚠️ Disk space issues during extraction.

Free up sufficient disk space on the destination drive before attempting to extract the file. CAB files can sometimes expand significantly.

Frequently Asked Questions

What is a CAB file used for?▼

CAB files are primarily used by Microsoft for software distribution, acting as compressed archives to package installation files, drivers, and system updates for Windows.

Can I open a CAB file on macOS?▼

Yes, you can open CAB files on macOS using third-party archive utilities like The Unarchiver or Keka, which support the CAB format.

Are CAB files safe to open?▼

Generally, yes, if downloaded from a trusted source like Microsoft. However, like any archive file, they can potentially contain malicious software if obtained from an untrustworthy website.

Technical Details

CAB files are typically identified by a specific header signature. They are internally structured using a folder index, a file index, and the compressed file data, often employing the Microsoft LZ compression algorithm.

Did You Know?

The term "Cabinet" refers to the original name for this file format.

Microsoft's Cabinet file format was developed as a successor to the Diamond compression format.

Security Information

CAB files are generally safe if downloaded from trusted sources like Microsoft. However, like any compressed archive, they can be used to distribute malware. Always ensure your antivirus software is up-to-date and scan downloaded files.