Just found squoosh.app - awesome. I'm always a little frustrated when I do a little PNG editing in Gimp and it produces a PNG that's double the original. Squoosh just squooshed 75% out of a Gimp PNG without making a change in quality that I can see. In this case - that's perfect.
@finity noice! I’ve had really good results with oxipng if you want a cli tool
