Loona GZIP Compressor - Squeeze One File into a .gz
Gzip is the compression workhorse of the web and of Linux: log files, CSV exports, database dumps and TAR archives all shrink dramatically under it. This page compresses one file to .gz with the Compression Streams API built into modern browsers - the fastest possible route, and entirely on your device.
Gzip compresses ONE file - it is not an archive format. To compress several files into one .gz, first bundle them with the TAR File Creator, then compress the .tar (that combination is exactly what a .tar.gz is). To turn a .gz back into the original file, use the GZ File Extractor.
How to use the GZIP Compressor
- Drop one file onto the box above, or click it and pick the file from your device.
- Click Compress to .gz. Your browser's own gzip engine does the work on your device.
- Compare the sizes in the summary: original, compressed, and the percentage saved.
- Click Download to save the .gz file. It opens with gzip, tar, 7-Zip, WinRAR - or our GZ File Extractor.
How it works
Gzip wraps the DEFLATE algorithm (LZ77 matching plus Huffman coding) in a small container: a 10-byte header starting with the magic bytes 1F 8B, the compressed data, and a checksum plus the original size as a trailer. This page feeds your file through the CompressionStream API - gzip compression implemented natively in Chrome, Edge, Firefox and Safari - so there is no JavaScript compressor to download and the work runs at native speed. One file in, one file out: gzip has no concept of folders, which is why the classic .tar.gz pairing exists - tar bundles, gzip squeezes.
Worked example
You drop access.log, a 4.2 MB web server log. Logs are repetitive text - the same addresses, timestamps and status codes over and over - so gzip crushes it to 380 KB, a 91% saving, and access.log.gz is ready to archive or email. Drop a 4.2 MB JPEG instead and the .gz comes out at 4.2 MB too: JPEG data is already compressed, and the page tells you so honestly instead of pretending otherwise.
Frequently Asked Questions
Is this GZIP compressor free?
Yes - free, no sign-up, no limits and no watermarks.
Are my files uploaded to a server?
No. Compression uses the gzip engine built into your browser (the Compression Streams API). Your file never leaves your device.
How do I compress several files into one .gz?
Gzip handles exactly one file. Bundle the files into a single .tar with the TAR File Creator first, then compress that .tar here - the result is a standard .tar.gz (just rename file.tar.gz if needed).
How do I get my original file back from a .gz?
Use the GZ File Extractor on this site - it reverses the process in your browser. On Linux and macOS, gunzip file.gz does the same job.
Why did my file get slightly bigger?
Already-compressed formats (JPG, PNG, MP4, PDF, ZIP) contain almost no repetition left for gzip to exploit, and the .gz wrapper adds a few bytes of header and checksum. For those files a tiny increase - usually well under 1% - is normal and harmless.