If you have ever run your website through Google PageSpeed Insights and been greeted with a low number in a red circle, you are not alone. Most small business websites score poorly on mobile, and most site owners have no idea what those numbers mean or what they should be aiming for.
This guide explains what a good website speed score looks like, what the different metrics mean, and what you can realistically do about a bad one.
What does the PageSpeed Insights score mean?
Google PageSpeed Insights gives your page a score from 0 to 100 based on a set of performance metrics measured in a simulated mobile environment. The score is broken into three ranges:
- 90 to 100 (green): Good. Your page loads quickly and provides a smooth experience.
- 50 to 89 (amber): Needs improvement. There are measurable performance issues that affect user experience.
- 0 to 49 (red): Poor. Your page has serious performance problems that are likely affecting bounce rate, conversions, and potentially search rankings.
The score is weighted across six metrics, but the most important ones are Largest Contentful Paint (LCP), Total Blocking Time (TBT, which correlates with Interaction to Next Paint), and Cumulative Layout Shift (CLS). These map directly to the Core Web Vitals that Google uses as a ranking signal.
What score should you be aiming for?
On mobile, aim for 75 or above. A score of 90+ is excellent but not always achievable on content-heavy sites, particularly those running WordPress with page builders. A mobile score in the 75 to 89 range means your site is performing well and your Core Web Vitals are likely in the green.
On desktop, aim for 90 or above. Desktop scores are almost always higher than mobile because the simulated device has more processing power and a faster connection. A desktop score below 70 suggests significant issues.
Here is a rough guide to what different score ranges mean in practice:
| Mobile Score | What It Means |
|---|---|
| 90 to 100 | Excellent. Fast load, good UX, strong Core Web Vitals. |
| 75 to 89 | Good. Minor issues but the site feels fast to visitors. |
| 50 to 74 | Needs work. Visitors are likely noticing the delay, especially on phones. |
| 25 to 49 | Poor. You are losing a significant portion of traffic to slow loads. |
| 0 to 24 | Critical. The site is barely functional on mobile. Immediate action needed. |
Most unoptimised small business websites score between 20 and 45 on mobile. That is the range where speed is actively costing you business.
Why the mobile score matters more
Google uses mobile-first indexing, which means it evaluates the mobile version of your site for ranking purposes. The mobile PageSpeed score simulates a mid-range phone on a 4G connection, which is much closer to what your real visitors experience than the desktop test.
If you only check your desktop score, you are seeing a misleadingly positive picture. Always prioritise the mobile score.
What matters more than the overall score
The overall score is useful as a quick health check, but the individual metrics underneath it tell you much more. Pay closest attention to:
Largest Contentful Paint (LCP): How long until the main content is visible. Google’s threshold for “good” is 2.5 seconds or less. This is usually the single most impactful metric. Common causes of poor LCP include oversized images, slow servers, and render-blocking scripts.
Cumulative Layout Shift (CLS): How much content moves around while loading. Google’s threshold is 0.1 or less. Images without dimensions, late-loading fonts, and dynamically injected content are the usual causes.
Interaction to Next Paint (INP): How quickly the page responds to user interaction. Google’s threshold is 200 milliseconds or less. Heavy JavaScript and third-party scripts are the most common culprits.
If all three of these are in the green, your site is in good shape regardless of the overall score number.
Lab data vs. field data
PageSpeed Insights shows two sets of results: lab data and field data.
Lab data is generated by running your page through a simulated environment with controlled conditions. It is repeatable and useful for diagnosing issues, but it does not reflect real user experience.
Field data comes from actual Chrome users visiting your site over the past 28 days (the Chrome User Experience Report). This is what Google uses for ranking purposes. Not all sites have enough traffic to generate field data, in which case you will only see lab results.
If your site has field data available, that is the most important section to look at. Lab data is useful for debugging, but field data tells you what your visitors are actually experiencing.
How to improve a bad score
If your score is below 50 on mobile, the most common fixes are:
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Compress and resize images. This is almost always the biggest win. Convert to WebP format, resize to the actual display dimensions, and implement lazy loading for images below the fold.
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Enable caching. Browser caching and server-side caching can dramatically reduce load times for returning visitors and reduce server load for everyone.
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Remove or defer unnecessary scripts. Analytics, chat widgets, pop-ups, and tracking pixels all add weight. Audit them and remove anything that is not essential.
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Review your hosting. If your Time to First Byte (TTFB) is over 600 milliseconds, your server is slow. Better hosting can cut seconds off your load time.
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Reduce plugin or app bloat. If you are on WordPress or Shopify, review your plugins and apps for performance impact.
These five steps will address the majority of performance issues on most sites. For a step-by-step walkthrough, see our guide on how to speed up WordPress. For a full diagnosis specific to your site, run our instant speed test or request a free speed check and we will tell you exactly what needs fixing and in what order.
A score is not the whole picture
A PageSpeed Insights score is a useful diagnostic tool, but it is not the ultimate measure of your website’s quality. A site can score 95 and still have usability problems. A site can score 72 and provide an excellent user experience.
Use the score as a starting point. Focus on the Core Web Vitals underneath it. And if your mobile score is below 50, take it seriously, because your visitors already are.
Frequently asked questions
What is a good Google PageSpeed score for mobile? Aim for 75 or above on mobile. A score of 90+ is excellent but not always achievable on content-heavy or WordPress sites. Anything above 75 means your Core Web Vitals are likely in the green and your site feels fast to visitors.
Is the desktop score or mobile score more important? The mobile score matters more. Google uses mobile-first indexing, meaning it evaluates the mobile version of your site for ranking purposes. The desktop score is almost always higher and gives a misleadingly positive picture.
Why is my mobile score so much lower than desktop? The mobile test simulates a mid-range phone on a 4G connection, which is much slower than a desktop on broadband. Images that load quickly on desktop take much longer on mobile. JavaScript that executes instantly on a fast processor blocks the main thread on a phone.
How often should I check my website speed score? Check after any significant change to your site: new plugins, theme updates, content additions, or hosting changes. For routine monitoring, monthly checks are sufficient. Google Search Console provides ongoing Core Web Vitals data if your site has enough traffic.
Can a website score 100 on PageSpeed Insights? It is possible on very simple, lightweight pages. Most real-world websites with images, forms, analytics, and interactive elements will not score a perfect 100, and that is fine. A score of 90+ is excellent. Focus on passing Core Web Vitals rather than chasing a perfect number.
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