Using CDN gets worse grades?


First want to say thanks for the site. Really helpful in so many ways.

Now to the reason for my post. I’ve been testing with CDN enabled and CDN disabled and I seem to generally get better grades here are webpagetest with CDN disabled. This seems counter intuitive to me. Is this accurate? Is there a reason why CDN would cause the grading of a website to go down?


Do you have links to test results?

How do the load times compare (those are a lot more important than grades)?

Which grades get worse with a CDN? The only one that should get worse is the Time to First Byte but that’s expected because of how the grade is calculated. If any of the other grades get worse then there is a config problem somewhere with how the CDN is set up (like if it isn’t compressing resources).