GZ Converter
FileFlip converts GZ files into 10 other formats entirely inside your browser, using libarchive compiled to WebAssembly. The GZ file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. There is no file-size limit and no account to create.
How do I convert a GZ file?#
- Drop your GZ file onto the converter at the top of this page, or click it to pick one from your computer.
- Choose the format you want out of it. FileFlip downloads the engine that conversion needs, once, and your browser caches it.
- Conversion starts the moment you pick the format, and the result is yours to download. The work happens in this tab, so nothing is uploaded and nothing is queued.
Is it safe to convert GZ files online?#
Yes, because nothing is uploaded. FileFlip converts GZ 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 happens to a GZ file#
FileFlip converts GZ into 10 formats with libarchive, all of it inside the browser tab. Each conversion below names the engine it uses, what it downloads, and exactly what that conversion keeps or drops.
| Category | Archives |
|---|---|
| File extension | .gz |
| FileFlip support | Read and written |
| Conversions available | 10 |
| Engines | libarchive |
| Downloaded to your browser | 1.0 MB on the first conversion, then cached |
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.
The GZ file format reference covers the specification, the programs that open one, and what each conversion keeps or drops.
GZ questions people ask#
Can a GZ file contain more than one file?
No, gzip compresses exactly one file or stream, so a .gz archive holding several files is actually a tar archive that's been compressed afterward, normally named .tar.gz or .tgz.
Why does gzip decompress so fast?
gzip uses the DEFLATE algorithm, which was designed for speed rather than maximum compression, so decoding it is cheap enough that web servers gzip-compress HTTP responses on the fly and browsers decompress them with no noticeable delay. Formats built for a tighter ratio, like bzip2 or xz, trade away some of that speed.
What does the .gz header actually store?
A gzip file's header can carry the original filename, the modification time and an operating system flag, and the file ends with a CRC-32 checksum of the uncompressed data plus its original size, all defined in RFC 1952. That checksum is what lets gzip detect a corrupted file on decompression.
Is gzip still used for anything besides old Unix files?
Yes, extensively. gzip is the default compression for HTTP responses across the web, and it's still the most common single-file compressor on Linux and macOS despite bzip2 and xz both compressing tighter.