GT Metrix and PageSpeed Insights with Cloudflare APO + CDN

I recently enabled Cloudflare APO with the CDN. Once setup, my peformance metrics are amazing when run through GT Metrix but the same pages are still showing slow metrics in Google’s Page Speed Insights.

For example in PageSpeed Insights I’m getting timings of 3.5s for “Largest Contentful Paint” but it’s 1.5s in GT Metrix. Both were tested and compared when using desktop settings, when running for mobile on both it the same just higher numbers.

Any idea why the improvements Cloudflare’s APO and CDN make are not picked up in PageSpeed insights?

It does have nothing to do with that. Its more likely that GtMetrix is using a different version of PageSpeed Insights or they are just meassuring differently or under different conditions.

For me (I do not have APO) its the same. In GPSI I do rank not as good as in GtMetrix. Always have been so. Also GtMetrix let you chose where to meassure from, PageSpeed Insights not. So you never know from where the test has been made.

Do not care about all this to much. What relly counts is if your visitors are getting served with a fast page!

Also: never use “Desktop settings” as they lowered the requirements for desktop very very hard. So its pretty easy to rank good on “Desktop settings” for every page. Mobile is what really counts. If your site is ranking good on mobile then it will be fast everywhere.

Largest Contentfull paint also depends on the hardware you are calling the page. the faster your processor the faster you can display/render/process the loaded files. Google limited this processorpower to match real-world scenarios. I think GtMetrix has not done this.

Also: Google exactly tells you what is wrong with your page and what they expect from your site and what exactly you should improve to rank better.


Could go a little bit more into details if you share your page or the test from both: GtMetrix & GPSI.

quoting myself from my write up at

For page speed tests, there are various tools online. Some are more useful and accurate for what they test. Some may use Google Lighthouse v6 engine but they use different servers or testing parameters so may not all show the same results i.e. whether cpu throttle on mobile tests is used or the network speed throttling is used and at what speed i.e. 3G, 4G, 5Mbp cable etc all my vary. Also, the tested web browser viewport size may differ which impacts how much of above fold viewport is rendered in the web browser and thus how many assets are rendered above the fold and below fold etc.

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Hi there. Thanks for the offer :slight_smile: Check out these links to see the differences I’m talking about.

Overall the site seems speedy and responsive when I use it but I want to ensure I am doing everything I can to stay in Google’s good graces.

Thank you

Pagespeed Insights for mobile uses throttled cpu and network connection equivalent to around Motorola G4 or Google Nexus 4 with 3G fast connection of 1.6Mbps for its lab tests but also reports field real world users and their real ISP connection speeds in top half. If you want to replicate Page speed insights elsewhere that is the mobile cpu and network throttling profile for mobile

While your GTMetrix test uses faster iPhone X/XS/11/12/12 mini/12 Pro with unthrottled net connection so will be faster and may reflect a real visitor’s experience


There is also something strange going on with your page.

When I just call your Page

And reload with:

F5 ==> cf-cache-status: HIT
CTRL + F5 ==> cf-cache-status: BYPASS

Maybe this is due to APO or something else, but on my page (with “Cache Everything”) this does not happen.

But in the end PageSpeed Insights tells you what you should improve.
most important was:

remove ressources which are blocking rendering.

If you want to see mor things you could/should improve, just read this post:

APO does not cache no-cache header requests and CTRL-F5 hard reload issues a no-cache header request


Thanks for the information. I just created a page rule to cache everything, is that the recommended approach? For all the other things, I had WP Rocket installed and it did a great job but it has incompatibilities with CloudFlare APO. Do you know of any developers that run a service to look at this holistically to resolve?

Yes and no. If you use APO it is actuelly not recommended. But if you never change the content of your pages you still can go with Cache Everything.

Please keep in mind that neither APO nor Cache Everything is the cause for the difference between the testresults of GtMetrix and GPSI.

It is just like @eva2000 stated above.

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