7Z to GZ Converter
FileFlip converts 7Z to GZ entirely inside your browser, using libarchive compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert a 7Z file to GZ?#
- Drop your 7Z file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to GZ and the conversion starts on its own. FileFlip downloads 1.0 MB of WebAssembly the first time and nothing after that, then runs libarchive on your own machine.
- Save the GZ file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting 7Z to GZ lose quality?#
No. Converting 7Z to GZ does not touch the files inside the archive. Each member is read out and written back byte for byte, so only the wrapper around them changes and nothing is recompressed.
Is it safe to convert 7Z files online?#
Yes, because nothing is uploaded. FileFlip converts 7Z files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What 7Z to GZ actually does to the file#
Converting 7Z to GZ runs on libarchive, downloads 1.0 MB of WebAssembly the first time and nothing after that, copies the archived files through unchanged, keeps file contents.
| Engine | libarchive |
|---|---|
| Conversion path | 2 steps: 7Z → the unpacked files → GZ |
| Downloaded to your browser | 1.0 MB, once, then cached by your browser |
| Quality | Lossless, contents copied unchanged |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| File contents | Kept | Carried through into the converted file. |
| File timestamps | Sometimes | Survives for some files and not others. |
| File permissions | Sometimes | Survives for some files and not others. |
Worth knowing before you start:
- the output is a PAX tar archive inside the compressor, not a single compressed stream
- every entry is extracted into memory before anything is written, so a very large archive can exhaust it
- no passphrase is passed to the reader, so an encrypted archive cannot be opened
What is a 7Z file?#
A 7z file is Igor Pavlov's archive container, most often holding data compressed with the LZMA or LZMA2 algorithm as one continuous solid stream rather than as separate per-file entries.
Use 7z when the files inside compress well together, such as source trees or similar documents, and the smallest possible archive matters more than universal compatibility.
Convert 7z to ZIP when the archive has to be opened somewhere without 7-Zip installed, since Windows and macOS still can't open 7z without adding software.
What is a GZ file?#
A GZ file wraps a single DEFLATE-compressed stream in a header that can carry the original filename and modification time, plus a trailing CRC-32 checksum, as defined in RFC 1952.
Use GZ to compress a single file quickly, especially one going over HTTP, where gzip decoding is effectively free.
Convert GZ to XZ when the same data needs to be as small as possible and slower compression is an acceptable cost.
7Z to GZ questions people ask#
Why are 7z files usually smaller than ZIP?
7z compresses the entire archive as one solid LZMA2 stream instead of compressing each file on its own, so repeated patterns across different files in the archive still count toward the compression. That solid approach is what gives 7z its size advantage over ZIP on a folder of similar files.
Why can't Windows open a 7z file without extra software?
Windows Explorer only has built-in support for ZIP, so opening a 7z file needs a separate program like 7-Zip, which is free. macOS Finder has the same gap and needs something like Keka or The Unarchiver.
Is 7z encryption safe?
7z supports AES-256 encryption, and unlike ZIP it can also encrypt the archive's file names, so a locked 7z doesn't reveal what's inside even without the password. The key is derived from the password with SHA-256 run over 2^19 iterations, which makes brute-forcing it slow.
Does 7z lose file permissions like Unix ownership?
The base 7z format doesn't store Unix file permissions or ownership the way tar does, so archiving a Linux directory tree as 7z can lose that metadata on extraction. Tools built around tar, including tar.xz, keep it.