GZ to TGZ Converter
FileFlip converts GZ to TGZ 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 GZ file to TGZ?#
- Drop your GZ 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 TGZ 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 TGZ file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting GZ to TGZ lose quality?#
No. Converting GZ to TGZ 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 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 GZ to TGZ actually does to the file#
Converting GZ to TGZ 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: GZ → the unpacked files → TGZ |
| 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
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.
What is a TGZ file?#
A TGZ file is the result of running tar to bundle files first and then gzip to compress that single resulting stream, packaged under one extension because DOS-era 8.3 filenames had no room for the two dots in .tar.gz.
Use TGZ for a Unix-style package or source release, where tar's metadata plus gzip's speed is the traditional, most widely supported combination.
Convert TGZ to TXZ when the smallest possible archive size matters more than compression speed.
GZ to TGZ 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.