hey! I was wondering how exactly webpagetest figures out if an image could be more compressed or not, so I could test/tweak stuff see if my site is generating the “right” sized images
i gave a shot at looking at the source and found this constant in wpt_test.cc:37 which looks like maybe a clue… →
It recompresses jpegs at a quality level of 85 which is pretty generous (usually you can go down to 75 without even thinking about it). The process also strips out meta-data like exif tags.
