optipng PNG image file optimization utility. Compress a PNG with default settings: optipng {{file.png}} Compress a PNG with best compression: optipng -o{{7}} {{file.png}} Compress a PNG with fastest compression: optipng -o{{0}} {{file.png}} Compress a PNG and add interlacing: optipng -i {{1}} {{file.png}} Compress a PNG and remove all metadata: optipng -strip all {{file.png}}