Brotli is a generic-purpose lossless compression algorithm that compresses data using a combination of a modern variant of the LZ77 algorithm, Huffman coding and 2nd order context modeling, with a compression ratio comparable to the best currently available general-purpose compression methods. It is similar in speed with deflate but offers more dense compression. It is open-sourced under the MIT License. You can browse its source code on Github. The specification of the Brotli Compressed Data Format is defined in RFC 7932.