Is your website retina-ready? Visualise aspect ratios for all images and backgrounds on the page
You have to download a csv to see which image is too big or too small. The csv isn´t displayed well in Google spreadsheats.. but the idea is nice
https://validator.ampproject.org/
NCC Group Web Performance
https://welldonecode.com
Tinkoff Journal
http://sites.google.com/site/haroldmartin/
chrisgallello
http://palette.site/
abbwebdev
http://emmet.io/
Kitze
http://emmet.io/
http://kzms2.xyz/
