Website Speed Test
Here's how I actually think about website speed test when I'm in the middle of a real project.
The short verdict
- Clarify the outcome
- Check the live SERP
- Change one thing, then measure
What I'd do first
- Clarify the outcome you need this week
- Check the live SERP for the query
- Change one page, then measure in Search Console
Plain-English take
A website speed test is a tool-based check that measures how fast a web page loads and identifies what is slowing it down.
What I got wrong
- Treating it as a one-off task
- Copying someone else's playbook without checking intent
- Measuring vanity metrics instead of the job-to-be-done
Next step
Quick answers
What is the best website speed test tool?
There is no single best tool. Google PageSpeed Insights is great for quick benchmarks and Core Web Vitals, while WebPageTest offers deeper diagnostics. Using multiple tools is recommended.
How often should I run a website speed test?
Run tests after any major site changes, and periodically (e.g., monthly) to monitor performance trends.
What is a good website speed test score?
For PageSpeed Insights, aim for 90+ on both mobile and desktop. For Core Web Vitals, targets are LCP <2.5s, CLS <0.1, and INP <200ms.
Sources
Primary documentation is linked directly. Anything commercial is marked nofollow.
- Google Developers — Official Google guidance for PageSpeed and site performance optimization.
- Google PageSpeed Insights — Google’s main public tool for measuring performance and getting optimization suggestions; widely used for SEO and web performance.
- WebPageTest — Widely respected for detailed performance diagnostics and advanced testing workflows.
Notes from Callum Bennett.