Experiment 004 QUEUED

Does a caching and image fix lift a WordPress site’s PageSpeed score by at least 20 points?

The hypothesis

What I expected — written before starting

A site-wide caching and image fix on a WordPress test site will raise its mobile PageSpeed score by at least 20 points, measured as the median of five runs before and five runs after.

The result

Not started yet

No result yet. The test is planned to start on 8 October 2026.

The details

Method, data and what I learned

This runs on a separate WordPress demo site, clearly a demo and not client work, so it can’t disturb this website.

The test

  • Run Google PageSpeed Insights five times on the demo site and record the median mobile score.
  • Apply one site-wide caching and image-optimisation fix, not a hand-edit of a single page.
  • Run PageSpeed Insights five more times and record the new median.

What counts as a win

The median mobile score rises by at least 20 points. PageSpeed results vary from run to run, which is why I use the median of five runs. If the “before” median is already above 80, a 20-point rise isn’t possible, and I’ll report that instead of a win or a fail.

What I can’t test yet

Whether the fix changes search position. The demo site is hidden from Google, so that half of the test will probably say “not enough data”. I report it separately and don’t count it toward the result.

Contact

Want this run on your site?

Let's connect

Contact me
Chat with me Usually replies within a half hour