Google mobile performance score: what it means and how to raise it
The mobile performance score summarises how fast your home page feels on a phone. Learn how it is built, why it varies and what moves it most.
2 min read
Area
Speed
Severity
High
Fix effort
Medium
Stores failing
16%
Of 165 stores we scanned where this check applies, 16% fail it and 21% pass. See all benchmarks.
The mobile performance score is Google's summary of how quickly your page loads and responds on a mid-range phone. Lighthouse produces a 0 to 100 number from several timings, and Google also assesses real visitors as fast, average or slow. This check uses the real-visitor verdict when Google has it.
Why it matters
Mobile traffic is the larger share of most store visits, and phones are slower than the laptop the store is built on. A score that looks fine on desktop can be poor on mobile because the phone has less processing power and a weaker connection.
The number is a summary, so it is best used to decide where to look and not as a target to hit for its own sake.
What the audit looks at
The audit uses Google's assessment of how the home page performs on mobile.
What usually causes it
- Large unoptimised images in the first screen
- Too many third-party scripts loading before the page is usable
- No page caching or a slow server response
- Heavy fonts and render-blocking CSS
How to fix it
Work through the individual speed findings; the score is their sum. The effort is medium, a theme or template edit that takes an afternoon.
- Treat the score as a summary, not a task. Fix LCP first -- it moves the score most and is what visitors actually feel.
- Re-measure a few times before and after: the score varies run to run, so a single reading is not a result.
How to check it yourself
- Run PageSpeed Insights on the home page and read the mobile tab.
- Note whether the top section shows real-visitor data. If it does, that verdict is the one that counts.
- Open the opportunities list and sort by estimated saving. Start at the top.
Frequently asked questions
Why is my score different every time I test?
Lab tests run on shared infrastructure and vary by a few points. Real-visitor data is steadier because it aggregates weeks of visits.
Does a 100 score matter?
No. A store that loads quickly for real visitors does not need a perfect lab score, and chasing the last points can cost more than it returns.
Related checks
Check your own store
See whether your store passes this check
Paste your store URL. The audit loads your pages in a real browser and shows the result for this check with the evidence behind it.