Compress or decompress text with GZIP entirely in the browser. View compression ratio and copy the result.
Frequently Asked Questions
GZIP is a widely-used data compression algorithm based on DEFLATE. It is the standard compression for HTTP responses, reducing transfer sizes by 60-90% for text-based content like HTML, CSS, and JSON.
This tool uses the browser-native CompressionStream and DecompressionStream APIs, which are available in all modern browsers. No data is sent to any server — everything runs locally in your browser.
GZIP produces raw binary data that cannot be displayed as text. Base64 encoding converts that binary output into a safe ASCII string so you can copy, share, and store it easily.
Typical text compresses 60-90% with GZIP. Highly repetitive text compresses better, while already-compressed or random data may not shrink much — or may even grow slightly due to GZIP header overhead.