CAB to 7Z Converter

Convert CAB archives to 7Z online with better compression

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Fast Conversion

CAB to 7Z conversion is handled entirely on our servers, delivering results in seconds without taxing your own machine.

Superior Compression

7Z's LZMA2 algorithm typically produces smaller archives than CAB — converting gives you better compression and broader compatibility.

Privacy First

Uploaded CAB files are deleted immediately after conversion. All output 7Z files are automatically removed within 24 hours.

How to convert CAB to 7Z

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose 7z or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your 7z file right afterwards

About formats

CAB (Cabinet) is a compressed archive format developed by Microsoft) for efficient software distribution and Windows component packaging. Introduced around 1996, CAB files serve as the container format for Windows Installer packages (.msi), Windows system updates, driver distributions, and ActiveX component downloads. The format supports three compression algorithms — MSZIP (Microsoft's Deflate implementation), Quantum (statistical compression), and LZX (an LZ77 variant with Huffman coding optimized for executable files) — with LZX typically delivering the highest ratios. CAB archives organize files into folders (compression units) where files within the same folder are compressed as a continuous stream for improved ratios, and archives can span multiple volumes for distribution on size-limited media. One advantage is deep Windows ecosystem integration — CAB files are handled natively by Windows without third-party software, used in everything from OS installation media to driver packages and system updates. The LZX compression algorithm provides another strength, achieving particularly strong compression on compiled code and PE executables, which is ideal for the format's primary role in software distribution. Microsoft's makecab tool ships with every Windows installation, and CAB extraction is built into Windows Explorer. The format continues to serve as infrastructure for Windows deployment and update mechanisms across enterprise and consumer environments.
Developer: Microsoft
Initial release: 1996
7Z is the native archive format of 7-Zip, an open-source file archiver created by Igor Pavlov in 1999. The format uses an open, modular architecture that supports multiple compression algorithms — LZMA and LZMA2 (the defaults), PPMd for text-heavy data, BWT, and Deflate — selectable per file within the same archive. LZMA typically achieves 30-70% better compression ratios than Deflate-based ZIP files on comparable data, making 7Z one of the most space-efficient general-purpose archive formats available. The container structure stores files with full directory hierarchy, timestamps, and attributes, while supporting solid compression (treating multiple files as a continuous data stream) for additional ratio gains on archives with many similar files. Encryption uses AES-256 with key derivation based on iterative SHA-256 hashing, and both file contents and filenames can be encrypted. One advantage is superior compression density — 7Z consistently produces smaller archives than ZIP or RAR on most data types, valuable when minimizing storage or bandwidth matters. The open architecture is another strength: the format specification and 7-Zip source code are publicly available under the GNU LGPL, enabling any developer to implement 7Z support without licensing constraints. Cross-platform tools supporting 7Z exist for Windows, macOS, Linux, and mobile platforms, and the format has gained widespread recognition as the preferred choice when maximum compression is the priority.
Developer: Igor Pavlov
Initial release: 1999

Frequently Asked Questions

Why would I convert CAB to 7Z?

7Z offers dramatically better compression than CAB and works cross-platform, so you get smaller files that anyone can open with free tools.

What software opens 7Z files?

7-Zip is the most popular free option. PeaZip and WinRAR also handle 7Z archives. macOS users can use Keka or The Unarchiver.

Is the folder structure kept during conversion?

Yes — all directories, subdirectories, and files inside the CAB archive are preserved exactly as they were in the resulting 7Z file.

Will converting to 7Z reduce the archive size?

In most cases, yes. 7Z's LZMA2 algorithm typically achieves better compression ratios than CAB's MSZIP or LZX compression.

Can I convert CAB to 7Z without installing software?

That is exactly what convertio.co is for — everything runs in the cloud, so no local installation is required on your end.

CAB to 7Z Quality Rating

4.3 (4 votes)
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