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Brotli.js is port of the Brotli compression algorithm (as used in the WOFF2 font format) to JavaScript. The decompressor is hand ported, and the compressor is ported with Emscripten. The original C++ source code can be found here.

Installation and usage

Install using npm.

npm install brotli

If you want to use brotli in the browser, you should use Browserify to build it.

In node, or in browserify, you can load brotli in the standard way:

var brotli = require('brotli');

You can also require just the decompress function or just the compress function, which is useful for browserify builds. For example, here's how you'd require just the decompress function.

var decompress = require('brotli/decompress');


brotli.decompress(buffer, [outSize])

Decompresses the given buffer to produce the original input to the compressor. The outSize parameter is optional, and will be computed by the decompressor if not provided. Inside a WOFF2 file, this can be computed from the WOFF2 directory.

// decode a buffer where the output size is known 
brotli.decompress(compressedData, uncompressedLength);
// decode a buffer where the output size is not known 

brotli.compress(buffer, isText = false)

Compresses the given buffer. Pass optional parameters as the second argument.

// encode a buffer of binary data 
// encode some data with options (default options shown) 
brotli.compress(fs.readFileSync('myfile.bin'), {
  mode: 0, // 0 = generic, 1 = text, 2 = font (WOFF2) 
  quality: 11, // 0 - 11 
  lgwin: 22 // window size