Google zolpfli

Google has introduced its latest data compression algorithm named Zopfli. Zopfli Compression Algorithm is a new open sourced general purpose data compression library. The term Zopfli is name from a Swiss bread recipe. It is implementation of the Deflate algorithm, which is used in the popular ZIP archive format, as well as in gzip file compression.

With Zopfli we can acquire output 3–8% smaller compared to zlib at maximum compression. The algorithm is written in C language. Zopfli is bit-stream compatible with compression used in gzip, Zip, PNG, HTTP requests, and others.

Google’s blog post says:

The smaller compressed size allows for better space utilization, faster data transmission, and lower web page load latencies. Furthermore, the smaller compressed size has additional benefits in mobile use, such as lower data transfer fees and reduced battery use. The higher data density is achieved by using more exhaustive compression techniques, which make the compression a lot slower, but do not affect the decompression speed. The exhaustive method is based on iterating entropy modeling and a shortest path search algorithm to find a low bit cost path through the graph of all possible deflate representations.

Due to the amount of CPU time required — 2 to 3 orders of magnitude more than zlib at maximum quality — Zopfli is best suited for applications where data is compressed once and sent over a network many times, for example, static content for the web. By open sourcing Zopfli, thus allowing webmasters to better optimize the size of frequently accessed static content, we hope to make the Internet a bit faster for all of us.