Zopfli
Zopfli Compression Algorithm is a compression library
Zopfli is a compression library and command-line tool that produces exceptionally small DEFLATE, zlib, and gzip streams by spending more CPU time to search for better encodings. It keeps strict compatibility with the ubiquitous DEFLATE format, so outputs can be decompressed by any standard tool or browser. The encoder performs exhaustive block splitting and greedy but thorough match searching to shave extra bytes off assets, which is ideal for web content and firmware where size matters more than compression time. A companion utility, zopflipng, targets PNGs by trying alternate filter strategies and recompressing IDAT chunks, often achieving additional savings without changing image quality. ...