This is a free online Gzip compression and decompression tool that runs entirely in your browser using the built-in CompressionStream API. You can compress text to Gzip format with Base64 or Hex output, or decompress Gzip-encoded Base64/Hex data back to original text. No data is ever uploaded to a server.
Web developers needing to compress data for frontend transmission can quickly verify Gzip compression effectiveness and ratios.
When debugging HTTP API responses with gzip encoding, use this tool to decompress and view original content.
Evaluate compression space savings for text data to help decide whether to enable gzip compression in your project.
Gzip is a compression format based on the DEFLATE algorithm, widely used for HTTP content encoding (Content-Encoding: gzip), file compression (.gz files), and log archiving. The browser CompressionStream API is a native compression interface available in modern browsers, requiring no third-party libraries. Compression level 1 is fastest with lowest compression, level 9 is slowest with highest compression, and level 6 is the default balance.
Completely safe. This tool uses the browser's built-in Compression API for local processing. All data stays in your browser and is never uploaded.
Chrome 80+, Firefox 113+, Edge 80+ and other modern browsers with CompressionStream API. IE is not supported.
Use the decompress feature. Paste the Base64 compressed string and click decompress to restore the original text.
Depends on content. Plain text typically compresses 60-80%. More repetitive content achieves higher ratios.
Depends on browser memory, typically tens of MB. For very long texts, process in segments.
Higher levels compress more thoroughly but slower. Level 1 is fastest with lowest compression, Level 9 is slowest with highest.