LZ77 Compressor
Compression · Free Online Tool
LZ77 sliding window compress/decompress for learning.
Click "Compress" to run...Sliding Window
Searches a 4 KB window for matches up to 18 bytes — the textbook LZ77 scheme.
Inspectable Output
Emits literal/match tokens as JSON so you can see exactly how the data was encoded.
Educational
Great for learning how deflate and LZ4 build on the LZ77 idea.
How to Use LZ77 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).
Zlib Compressor
Zlib format (RFC 1950) compress and decompress.
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.
Learn the concept
Learn the concept
Understand the programming ideas behind this tool.