Unzip Files

What is a ZIP file?

A ZIP file bundles many files and folders into one, usually compressing each of them. Besides .zip files, the same format sits inside .jar, .apk, .epub, .docx and .xlsx files.

This tool unzips files in your browser, with nothing to install. Open a ZIP to list what is inside, or extract the files to download.

• ZIP file: up to 100 MiB. The whole file is read, because a ZIP keeps its index at the end. Archives with up to 65,535 entries open here, and the listing shows the first 10,000.
• What to do: Extract files or List contents. List shows every entry with its size, packed size, method, date and whether it is encrypted, without decompressing anything. Extract returns the files themselves.
• Only these paths: optional glob patterns, one per line or separated by commas, matched without regard to case. A pattern without a slash also matches file names in any folder, so *.csv picks every CSV file. A pattern ending in a slash, such as docs/, picks everything under that folder. Leave it empty to extract every file.
• Password: for encrypted archives, both the older ZipCrypto scheme and WinZip AES. Listing works without it.
• One run extracts up to 100 files and up to 200 MiB. Asking for more is refused before anything is decompressed, with the count, so you can narrow the paths.
• Each download is named after its path inside the archive, with slashes turned into dashes.

The compression methods it reads are stored, Deflate, Deflate64, bzip2, LZMA, XZ, Zstandard and PPMd, plus Shrink, Reduce and Implode from early PKZIP versions.

Why use a browser page for this

The archive and its password stay on your device. That matters when the ZIP holds contracts, exports or anything you would rather not upload to a stranger's server, and when you are on a borrowed or locked-down computer that has no archive program.

The page is also careful about what it extracts. Entries with absolute paths, drive letters or .. in their names are listed but never extracted. So are folders, symlinks, the __MACOSX resource forks that macOS adds, and a path that appears twice. A ZIP inside the ZIP comes out as a file and is not opened. A header that understates a file's size cannot get past the 200 MiB limit, because the limit counts the bytes actually written.

Are there alternatives?

Windows, macOS and most Linux desktops open ZIP files with a double click. 7-Zip and The Unarchiver handle larger ZIP files and also open 7z and RAR archives, which this page does not.

For a .tar, .tar.gz or .tar.xz archive, use Open TAR and TAR.GZ Files on ToolkitBay. To build a ZIP from your own files, use Create ZIP File.

Fun facts and more info

Phil Katz's PKZIP introduced the format in 1989, and PKWARE still publishes its specification as APPNOTE.TXT.

Because the index sits at the end, a ZIP can carry other data in front of it. That is how self-extracting .exe archives work, and why this page needs the whole file before it can list anything.

ZipCrypto, the original password scheme, is weak. A known-plaintext attack can recover the keys, and its quick password check lets about 1 wrong password in 256 through, which then fails when the file is checked. Use AES when the contents matter.