Loona 7Z File Extractor - Open 7Z Files Online
The .7z format from 7-Zip squeezes files smaller than almost anything else, which is why game assets, ROM packs, backups and big log bundles so often arrive as .7z. The catch: neither Windows nor phones open it out of the box. This page does, using a WebAssembly port of libarchive that runs entirely on your device.
How to use the 7Z File Extractor
- Drop your .7z file onto the box above, or click it and pick the file from your device.
- Wait a moment while the archive is read - on first use the extraction engine (about 1 MB) loads once and is then cached by your browser.
- Browse the list of files inside the archive, with the size of each one.
- Click Download next to any single file, or use Download all as ZIP to save everything as one standard ZIP file.
How it works
7z archives usually compress data with the LZMA or LZMA2 algorithms, which is why they beat ZIP on text-heavy content. This page reads them with libarchive compiled to WebAssembly: the engine parses the 7z header, decodes the folder structure, and lists every entry with its uncompressed size. Files are decompressed only when you download them. The Download all as ZIP option re-packs the extracted files with JSZip, so the result opens on any system without 7-Zip.
Worked example
You download a game mod as weapons-pack.7z (42 MB). The page lists 31 files: textures, a readme.txt and an installer folder. You read the readme first by downloading just that one file (12 KB), check it is the mod you wanted, and only then download the rest as a ZIP - instead of installing software to peek inside.
Frequently Asked Questions
Do I need 7-Zip installed to use this?
No. That is the point of this page - the 7z format is decoded by a WebAssembly engine inside your browser, so nothing needs to be installed on your computer or phone.
Which 7z compression methods are supported?
The standard ones used by 7-Zip: LZMA, LZMA2, BZIP2, PPMd and plain copy (stored). Archives made with default 7-Zip settings open fine - the LZMA, LZMA2 and BZIP2 variants were all verified against real test archives when this tool was built.
My 7z file asks for a password. Can this tool open it?
No. Encrypted 7z archives (including ones with encrypted headers, where even the file list is hidden) are not opened, and the tool never tries to guess or crack passwords. Use 7-Zip with your password to unpack it instead.
Why is the extracted ZIP sometimes bigger than the .7z?
Because 7z with LZMA2 usually compresses better than ZIP's DEFLATE, especially on similar files packed together (solid compression). The files inside are identical - only the packing is less tight.
Are my files uploaded anywhere?
No. Everything runs in your browser tab on your own device. The archive and its contents never touch a server, which also makes this safe for private files.
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