Discrepancy in Page Speed Analytics: Cloudflare vs Google Test

Hello Cloudflare community,
I’m reaching out to seek guidance on a puzzling observation I’ve made regarding page speed analytics for my site. I’ve noticed significant differences in the results between Cloudflare’s built-in speed test and Google’s PageSpeed Insights test.

When I run a speed test on my site using Cloudflare’s tool, I get the following results:

  • First Contentful Paint (FCP): 0.39s
  • Largest Contentful Paint (LCP): 0.94s

However, when I run the same test using Google’s PageSpeed Insights, I get the following results:

  • First Contentful Paint (FCP): 2.7s
  • Largest Contentful Paint (LCP): 2.7s

As you can see, there’s a significant discrepancy between the two tests, with Google’s test indicating much slower page load times.
My initial guess, based on manually compressing one image and seeing decent results, is that unoptimized images and code that could use a few KBs of minification might be contributing to the slower page load times reported by Google’s test. However, I have a lot of images on my site, and manually compressing them all would be a significant undertaking. I’m wondering whether I can automatically optimize these elements through some setting in Cloudflare, rather than having to manually minify and compress them, and then update a whole new deployment.

Any insights or guidance would be greatly appreciated.
Thanks in advance for your help.