Zopfli is *really* good at compressing PNGs

> I sourced test images from: > In total, this amounted to 336 test images.

Nice post, it's good to have data like this!

For PNG images I crop with GIMP (magnified to 800% so I can cut down to the pixel), then reduce the color depth with pngquant, then compress with zopflipng. The result is excellent, even better than WebP (which is almost always better than unoptimized PNG). Haven't experimented enough with AVIF yet.