Zlib Compressor
Compression · Free Online Tool
Zlib format (RFC 1950) compress and decompress.
'deflate' to the zlib format (RFC 1950). If you need raw deflate (no header), use the Deflate-Raw tool.Click "Compress" to run...RFC 1950 Framing
Produces a 2-byte zlib header (CMF/FLG) and an Adler-32 checksum trailer around the deflate stream.
Native & Fast
Backed by the browser's built-in CompressionStream — no third-party libraries needed.
Base64 Transport
Output is base64-encoded for safe copy/paste between systems.
How to Use Zlib Compressor
- 1Enter or paste the text you want to compress.
- 2Select the compression algorithm (gzip, deflate, or brotli).
- 3Click compress to reduce the data size.
- 4Copy or download the compressed output.
Features
- ✓100% free — no signup, no subscription, no ads
- ✓Runs entirely in your browser — data never leaves your device
- ✓Fast and lightweight — instant results
- ✓Cross-platform — works on desktop, tablet, and mobile
Frequently Asked Questions
What compression algorithms are supported?
We support gzip, deflate, and brotli compression algorithms for text data.
Is there a file size limit?
Since tools run in your browser, the limit depends on your device memory. Most tools handle several megabytes without issues.
Related Tools
Gzip / Brotli Compressor
Compress and decompress text with gzip and deflate streams.
Deflate Compressor
Deflate algorithm compress/decompress (native CompressionStream).
Raw Deflate Compressor
Raw Deflate stream without zlib header compress/decompress.
LZ-String Compressor
lz-string compress/decompress for short text in URLs/LocalStorage.
LZUTF-8 Compressor
LZUTF-8 compress/decompress optimized for UTF-8 text.
LZMA Compressor
LZMA/LZMA2 high-ratio compress and decompress.
Learn the concept
Learn the concept
Understand the programming ideas behind this tool.