GZIP compressor & decompressor
Compress or decompress GZIP text right in your browser: paste some text, JSON, or a compressed token, pick Base64 or hex, and get the result instantly.
How it works
This tool uses the browser's own Compression Streams (CompressionStream/DecompressionStream) — the same GZIP mechanism web servers use to compress HTTP responses, not a JavaScript reimplementation or an external library. When compressing, the result is shown as Base64 or hex, because raw GZIP bytes can't be pasted as text without getting corrupted.
When you'd need this
This comes up a lot while debugging: a compressed payload inside a cookie, a URL parameter, or a JWT token (some carry a GZIP+Base64-compressed claim); or when checking exactly what your own backend compressed before storing or sending it.
Real .gz files
When decompressing, you can also upload a .gz file directly (say, one downloaded from a server or produced by gzip on the command line), instead of pasting the encoded text by hand.
When the result isn't readable text
When you decompress data that wasn't text to begin with (an image, some other binary format), the result can't be shown as UTF-8 text — the tool detects that, warns you, and lets you download it as a binary file instead of trying to display it broken.