7-Zip

7-Zip is a free, open-source file archiver for Microsoft Windows – released under the GNU LGPL license, of course. It's one of the better (probably THE most popular) free file compression programs you can find, giving you a really good compression ratio.

The main archive format is 7z, but it works with many others (both reading and writing them - see below under the "Features" section). You’ve got a few ways to use it: through the graphical interface – most folks use that – a command line version, or integrated into Windows (all versions being available on the official 7-Zip website (though, we list the most popular ones on dAppCDN too).

Features

• High compression ratio with *7z format using LZMA/LZMA2 methods
• Supports packing and unpacking 7z, ZIP, TAR, BZIP2, GZIP, XZ, and WIM formats
• Can unpack things like RAR, RPM, ARJ, CAB, CHM, and more – quite a list, really
• Good compression ratios for ZIP and GZIP formats (around 2 to 10% better than others)
• AES-256 encryption for 7z and ZIP formats – essential for keeping things secure Windows integration for easy use
• Self-extracting archives for 7z format File Manager and command line options Plugin for FAR Manager
• Supports many languages (87 translations last time I checked on the official 7-Zip website)
• Calculates hash checksums: CRC-32, CRC-64, SHA-1, SHA-256, and more
• Works with systems that have a lot of CPU threads (over 64 – added in version 25.00)

Please note: The 7z format has some of the highest compression rates you'll see (probably around 30-70%), using LZMA and LZMA2 (algorithms for lossless data compression), which is likely why it's become the most popular free file archiver.

**7-Zip – A Closer Look ** The current version (while I am writing this) is 25.01! Igor Pavlov (the author) released this update in August 2025. And yes, it remains free and open source. There have been updates since 2020, including ZSTD archive support and a fix for a security issue. Version 25.00 added support for systems with more than 64 CPU threads.

Usually when I write about file archiving apps, my first two words are related to archive and unarchive. Maybe a bad habit considering I am now an old guy and some of you might remember the old WinZip and the WinRAR days.

While these are frequently used together (and I tend to use them as well - mea culpa) they are not the same thing.

Archive means that you combine files/folders in a single file without reducing their size) Compressing means that you use an algorithm to reduce the total size of files.

7-Zip does this: it is able to compress and decompress your files.

The main reason why you would want to do it is related to speed (sending a smaller file) and security (you can protect your files with a password and encryption).

Back in the days I would've added another argument: to save space but that is not the case anymore considering the HDD/SSD space is cheaper now. I would say that anything related to a secure backup makes sense. Let's say that you want to store a backup somewhere of your files (encrypted/password protected - of course). You can do it and then move it to another storage device or to a secure cloud.

So, with 7-Zip it is easy to back up files and secure your data. 7-ZIP supports lots of compressed file types like BZIP2, 7z, TAR, and ZSTD. The decompression support list is even longer. It can decompress all sorts of formats like AR, ARJ, CAB, DMG, FAT, ISO and more.

For many, the ability to quickly and cleanly compress and decompress ZIP and RAR files with a free application is enough. Most users stick with those formats, making 7-Zip a really good choice. Everything else (features) is just a bonus.

If you’re used to programs like this (I mentioned WinZip or WinRAR because they were old and popular), you’ll appreciate 7-Zip's fast compression rates. Version 25.00 improved bzip2 compression speed by 15-40%, and deflate compression got a bit faster too. It achieves this by being lightweight. If you compress and decompress lots of files, and you aren't using 7-Zip, you really should be.

I might add that recent versions have added useful features. Version 24.03 introduced a filter for better compression of executable files. Version 24.04 added a menu item to delete temporary files. Version 24.09 increased decompression speed on ARM64 versions. The program can now ask permission before unpacking large RAR archives. Anyway - I am not going to list the entire changelog, you can check it here: https://www.7-zip.org/history.txt

My Experience

I will be honest: 7-Zip looks like it was designed in 1998 and the developer didn't bother to update how it looks - I would say he invested all of his time in functionality. But as I stated multiple times on dAppCDN, I don’t care about shiny buttons; all I care about is performance.

That being said, you can use 7-Zip in a couple of ways.

You can open the main window and work with files there, or use the context menu – a simple right-click.

7-Zip is probably the most honest software you will ever install. It is free, open-source (GNU LGPL), and it doesn't nag you with "Please buy a license" pop-ups like other paid alternatives.

Just a soft note: Unlike some tools, you need to select files first, then compress them. If you are a beginner you might find the configuration settings a bit confusing, particularly if you're new to programs like this. If you're unsure, just leave the settings as they are, and it’ll work fine.

Apart from the features and options I would like to mention two things that are important to me:

7-Zip consistency is top. As far as I'm aware it was always open-source and has no hidden tracking or ads since 1999 - that is 27 years (while I am writing this review)

Can it open RAR files? That sounds so lame but that's exactly how I discovered this software. I was looking for a WinRAR alternative. Yes, it can extract them. It cannot create RAR files because that format is private, but it handles almost any other file type you throw at it.

Finally, the 7z format gets you some of the highest compression you’ll see available (using LZMA and LZMA2 – it’s an algorithm for lossless data compression), which is likely why it's become the most popular free file archiver.

7-Zip is among the first apps (we used to call them programs/software) I install after a fresh Windows setup.

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