PageSpeed determines your score based on a wide variety of factors like timings of important rendering events, execution times, download times, etc. With every test, these factors vary slightly, resulting in a slightly different score. It is normal to see differences with up to 5 points, and this is not a cause for concern.
Why Do PageSpeed Insights Scores Vary?
Several factors can cause variability in your PageSpeed Insights scores between tests:
1. Server Response Time
Fluctuations in the time it takes for your server to respond can alter the performance scores. This is influenced by server load or backend configurations.
2. Network Latency and Geographic Testing Location
Testing your website from different geographic regions can lead to varying results due to differences in network latency or the physical distance from the server being tested.
3. Temporary Cache and Reoptimization
When website updates are made, the cache for affected pages may be purged temporarily, causing unoptimized performance during initial tests. Reoptimized pages will yield improved scores on subsequent tests.
4. Variability in Test Repetition
Running the same test repeatedly can naturally produce slightly different results due to the dynamic nature of computational measurements.