This is a nice visualization tool for seeing how these fonts will scale in your browser. Nice job!
I always consider: That 9px text might look readable on your 4K iMac, but how about your users on a budget Chromebook with a 720p display? And text rendering differences between browsers and operating systems is still something that severely affects how the text looks, especially at thin font weights that seemed to be all the rage a few years ago.
I always consider: That 9px text might look readable on your 4K iMac, but how about your users on a budget Chromebook with a 720p display? And text rendering differences between browsers and operating systems is still something that severely affects how the text looks, especially at thin font weights that seemed to be all the rage a few years ago.