This page demonstrates LZMA.JS: an implementation of the LZMA compression algorithm in JavaScript. It is a standalone version of the GWT-LZMA compression module. LZMA.JS will use web workers, if available, which allows the browser to remain interactive even while compressing/decompressing large amounts of data. It will also gracefully degrade on older browsers that do not support web workers. (It even works on IE6!) You can find a simpler demo here.

Compressing: Enter any content into the left window and press "Compress" to compress it. When finished, the right window will display the hexadecimal representation of the compressed content of the left window (after encoding it in UTF-8). Use the pulldown to choose from fastest (Level 1) to best (Level 9) compression—lower levels are more appropriate for JavaScript running in a browser.

Decompressing: Enter whitespace-separated hexadecimal bytes in the right window corresponding to compressed output of the LZMA algorithm. Press the "Decompress" button to decompress the data and the original will be shown back in the left window (decoded from UTF-8).

On UNIX machines, you can generate input for the right window yourself using commands like this:

$ echo "Hello, world." | lzma -3 | hexdump -C | cut -c9-60

Warning: The LZMA algorithm was not originally designed to run in a browser. Use of the higher compression levels (in either direction) and/or large files may cause your browser to explode.

This JavaScript application runs entirely within your web browser.