Compress a file to a .gz file locally - lossless, with a selectable level, no upload, right in your browser.
Running locally on your device ...
0%
Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Gzip (.gz) is a lossless compressor for single files - common for log files, backups, database dumps and on the web (Content-Encoding: gzip). Unlike ZIP, gzip does not bundle multiple files; it compresses exactly one file particularly efficiently.
Compression runs locally in your browser (fflate, pure JavaScript, DEFLATE). The level (1-9) controls the trade-off between speed and file size. Nothing is uploaded.
Text-like content with many repetitions benefits the most: verbose logs, CSV exports, SQL dumps or source code can often shrink to a fraction. That is exactly why web servers deliver pages gzip-encoded and save bandwidth. If instead a whole folder should be combined, bundle it as a TAR first and pass the result through here - that yields the common .tar.gz suffix.
| Output format | GZ |
|---|---|
| Batch processing | No |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: Gzip compresses exactly one file (for several, create a TAR or ZIP first). Already compressed files (JPG, MP3, ZIP) barely shrink. One file per run.
No. Compression runs entirely locally in the browser.
Higher (9) compresses harder but slower; lower (1) is faster but larger. The preset is level 6 - the usual compromise the gzip command-line tool uses as well. Text files such as CSV, JSON or logs often shrink by 60 to 80 percent; already-compressed formats barely at all.
Gzip packs only one file. For several, create a TAR first, then gzip it.
Yes. Decompressing gives you back exactly the original file.