ZIP vs 7z vs RAR: what actually differs
Haven Zip team · · 2 min read
People pick an archive format the way they pick a text editor: whatever was there first. That is fine until you need to send a file to someone on a different system, protect it with a password, or squeeze a large dataset. Then the differences matter, and they are not the ones most comparison tables list.
Compatibility is the real deciding factor
ZIP opens everywhere without installing anything: Windows Explorer, macOS Finder, every Linux desktop, iOS Files, Android's file manager. That alone is why it remains the default for anything you send to someone else.
7z needs 7-Zip, Keka, PeaZip or a similar tool on the receiving end. RAR needs WinRAR or a viewer that licenses the decoder, since the format is proprietary; open-source tools can extract RAR but may not create it. If the recipient is not technical, ZIP wins before compression is even considered.
Compression ratio
On text-heavy data 7z with LZMA2 typically produces archives 20 to 40 percent smaller than ZIP with Deflate. RAR5 lands between the two. On already-compressed media all three are within a rounding error of each other, because there is nothing left to compress.
7z also supports solid archives, where files are compressed as one continuous stream. Ten similar documents share a dictionary and compress far better than as ten separate entries. The cost is that extracting a single file from the middle means decompressing everything before it.
Encryption
Classic ZIP encryption, called ZipCrypto, is weak and should be treated as no protection at all. Modern ZIP tools use AES-256, but a receiver's built-in extractor may not support it. 7z encrypts with AES-256 by default and can also hide the file names. RAR5 uses AES-256 as well.
If the password matters, use 7z or an AES ZIP and tell the recipient which tool to use. Haven Zip creates AES-256 protected 7z and ZIP archives on your device and opens password-protected RAR, 7z and ZIP.
Licensing and longevity
ZIP is documented in a public specification and has been implemented independently hundreds of times. 7z is open source under the LGPL and the format is fully documented. RAR's compression is proprietary; only the decompressor source is available, with a license that forbids using it to build a RAR creator.
For archives you expect to open in twenty years, an open, widely implemented format is the safer choice. That points at ZIP for convenience and 7z for size.
- Sending to anyone: ZIP.
- Smallest size, especially for text or many similar files: 7z.
- Received a RAR: extract it and re-pack as ZIP or 7z if you need to keep it.