How JustUnzip Works
JustUnzip uses cutting-edge browser technology to extract archive files without ever uploading them to a server. Here's how it works.
Three Simple Steps
Drop Your Archive
Drag and drop any ZIP, 7z, RAR, TAR, or compressed file onto the tool. You can also click to browse your files.
Instant Processing
The archive is processed entirely in your browser using WebAssembly. You'll see the contents listed within seconds.
Download Files
Click to download individual files or use "Download All" to save everything. Files go straight to your downloads folder.
The Technology
Powered by WebAssembly
JustUnzip uses libarchive compiled to WebAssembly (WASM). This means the same battle-tested code used by Linux and macOS systems runs directly in your browser at near-native speed.
Industry-standard archive library supporting 50+ formats, compiled to run in browsers.
Near-native performance in the browser. No plugins, no installations required.
All processing happens on your device. Zero data transmission to any server.
Handle files up to 2GB depending on your device's memory. No artificial restrictions.
Supported Formats
JustUnzip can extract virtually any archive format you'll encounter:
- ZIP - The universal archive format
- 7-Zip (.7z) - High compression ratio archives
- RAR - Popular for large file downloads
- TAR - Unix/Linux tape archives
- GZIP (.gz, .tar.gz, .tgz) - Compressed files and tarballs
- BZIP2 (.bz2, .tar.bz2) - High compression format
- XZ (.xz, .tar.xz) - Modern compression standard
Why Browser-Based?
Traditional archive tools require you to either install software or upload files to a server. JustUnzip eliminates both problems:
- No Installation - Works instantly on any device with a modern browser
- No Uploads - Your files never leave your device
- Works Everywhere - Chromebooks, phones, tablets, restricted work computers
- Always Up-to-Date - No software to update or maintain
What This Means for Your Privacy
- Your archive files are never uploaded to any server
- No third party receives or processes your files
- We have no access to the content of your files
- No file data, filenames, or metadata are logged or stored
- Files exist only in your browser's memory during processing
How to Verify
You do not have to take our word for it. Here is how to confirm:
- 1 Open your browser's developer tools (press F12, or right-click and choose Inspect)
- 2 Go to the Network tab
- 3 Use the tool to extract an archive
- 4 Observe: no outbound requests contain your file data
Alternatively, disconnect from the internet after the page loads. The tool continues to work — because it requires no server.
Trade-offs and Limitations
Because processing happens entirely in your browser, performance depends on your device's hardware and available memory. Very large archives (over 1GB) may take longer on low-powered or low-memory devices compared to server-based tools. This is the trade-off for keeping your files completely private.