PageSpeedInsights gives to my website a poor note (64/100) compared to Pingdom Tools note (91) . However, I have good practices in developing this website, optimizing images, CDN, gzip, minify, browser cache...
The optimisation suggested are really basics, for example, reduce css files to gain 83ko even if all css files are minified, optimizing optimized images..
Have you an explanation about why my score is poor? What are differences between these two tools ? How can I improve this score ?
Thanks for your help,