What is a .ZIP file?
ZIP is the most common archive format, bundling and compressing multiple files into one. Built into Windows, macOS and tools like 7-Zip.
- Did you know
- Phil Katz created ZIP in 1989 for his PKZIP tool, and it remains the world’s default archive format.
- ZIP keeps a “central directory” listing all its contents at the very end of the file, so a reader can see the catalogue without scanning everything.
- Its usual compression is DEFLATE, a scheme Phil Katz devised that pairs LZ77 matching with Huffman coding.
- Katz released the ZIP format specification publicly while keeping his PKZIP program itself as shareware, helping the format spread everywhere.
- On the web a .ZIP file is served with the MIME type
application/zip.
- What Analyser shows you
- Browse the file tree and compression details of archives without extracting them: ZIP in pure JavaScript, and RAR, 7z, TAR and compressed tarballs (.tar.gz / .tgz, .tar.xz, .tar.zst, .tar.bz2) through a bundled libarchive engine - click any file inside to analyse it. A single compressed stream (.gz, .xz, .zst, .lz4, .lzma, .Z) is decompressed so the file within can be opened; bare .bz2 streams are identified only.
- Open a .ZIP file
- Drag a .ZIP file onto the Analyser home page (or tap to pick one). It opens entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.