Compress Decompress
Compress and decompress text and files.
Text to compress
Compress and decompress text with gzip online
Compress/Decompress uses your browser's built-in gzip engine — the same standard used for .gz files and HTTP compression — to shrink text and reverse the process.
Why use this tool
Real gzip compression
Uses the browser's native CompressionStream API, implementing the same DEFLATE/gzip algorithm as command-line gzip.
Round-trip decompression
Paste back the base64 output to decompress it and verify you get your original text back.
Size comparison
See exactly how many bytes you saved (or didn't) — compression works best on longer, more repetitive text.
No upload required
Compression and decompression both happen locally in your browser.
How it works
- 1Choose Compress or Decompress.
- 2Paste your text (or base64 gzip data, for decompress).
- 3Click the button and copy the result.
Frequently asked questions
Good to know
- Uses your browser's native gzip implementation — the same algorithm behind .gz files and HTTP Content-Encoding: gzip.
- Very short text can end up larger after compression due to gzip's header overhead — this is normal.
- Compressed output is shown as base64 text so it's easy to copy and paste.