ACID3 is impossible to score 100/100 while respecting modern standards: https://news.ycombinator.com/item?id=15256890

ACID2 looks fine to me in Firefox 72, but then, it doesn't show a score, so...

Acid2 fails in a strict sense if 1 image pixel != 1 device pixel != 1 CSS pixel.

For Acid3 there's http://wpt.live/acid/acid3/test.html which reflects what browsers are actually targetting (and is what runs in everyone's CI system): see https://github.com/web-platform-tests/wpt/commits/master/aci... for the history.

I was running ACID2 on a retina display and it is very distorted around the eyes in Firefox. Chrome did render it ok.