ZIP file format
ZIP archive
ZIP is the universal archive format: it bundles files and folders into one compressed file that Windows, macOS, Android and iOS can open without extra software.
| Property | ZIP |
|---|---|
| File extensions | .zip |
| MIME type | application/zip |
| Introduced | 1989 by Phil Katz (PKWARE) |
| Compression method | DEFLATE (per file) |
| Password protection | Yes (ZipCrypto or AES) |
| Open source format | Yes (published spec) |
| Built into Windows / macOS | Yes — both open ZIPs natively |
| Best for | Sending many files as one, universal compatibility |
What is a ZIP file?
ZIP was created by Phil Katz of PKWARE in 1989. Each file inside is compressed separately, usually with the DEFLATE algorithm, and a central directory at the end lists every entry — which is why you can open one file without extracting the rest.
Strengths and weaknesses
ZIP's killer feature is compatibility: every major operating system opens it natively. It compresses less tightly than 7z or RAR, and already-compressed files (JPG, MP4, MP3) barely shrink at all.