ZIP vs 7Z: which archive format should you use?
Compare ZIP and 7Z on compression ratio, compatibility, encryption, and speed to pick the right format.
ZIP and 7Z are both archive formats, but they solve different problems. ZIP is the universal standard that every operating system opens natively. 7Z often compresses more aggressively, but it requires specific software on the receiving end.
The short version
Use ZIP when sharing files with other people, because it opens everywhere. Use 7Z when you control both ends of the transfer and the smaller size is worth the compatibility cost.
Compression ratio
7Z files are usually smaller than ZIP files for the same contents. 7Z supports LZMA and LZMA2, which find more redundancy than the DEFLATE method used by standard ZIP files. The trade-off is speed: stronger compression takes more time and memory.
Compatibility
ZIP wins decisively. Windows Explorer, macOS Finder, Android, iOS, and every major archive tool open ZIP files without extra software. 7Z requires 7-Zip, WinRAR, or another tool with 7Z support.
Encryption
Both formats support password-based encryption. 7Z's AES-256 implementation is generally considered strong, and modern ZIP tools also support AES-256. Aback ZIP does not process password-protected archives.
Which should you choose?
- Sharing with others: ZIP, always.
- Archiving your own data for maximum savings: 7Z is worth considering.
- Sending to a mix of devices and people: ZIP.
- Already-compressed files: neither helps much, so use ZIP for compatibility.
Frequently asked questions
Is 7Z always smaller than ZIP?
Usually, but not always. For already-compressed data such as JPEG, MP4, or PDF, both formats save little and 7Z may even add overhead.
Can ZIP files use 7Z compression?
The ZIPX extension allows newer methods, but standard ZIP tools may not read them. For maximum compatibility, stick to standard ZIP.