Another option using zopfli is pngtastic (disclaimer, my own project): https://github.com/depsypher/pngtastic https://github.com/depsypher/pngtastic It really

Another option using zopfli is pngtastic (disclaimer, my own project): https://github.com/depsypher/pngtastic https://github.com/depsypher/pngtastic It really is significantly slower, but if you want to reduce every last byte in a png zopfli is your best bet.