You ran a speed test. A number came back in the 30s or 40s. Now you're wondering whether that's just how websites work, or whether something is genuinely wrong. This post gives you a straight answer, without the technical lecture.
What the score actually is
The PageSpeed score comes from Lighthouse, a testing tool built and maintained by Google. When you run a test on your site, Lighthouse simulates loading your page on a mid-range mobile device, on a mid-range mobile data connection. Not your fast home broadband. Not a high-end phone. The average.
That matters because most of your visitors are on exactly that kind of setup. The test is designed to reflect reality, not ideal conditions. A site that performs well in a fast office on a laptop might still be painfully slow for someone searching for you on a phone from a car park.
The scores run from 0 to 100. Google's thresholds are:
A score in the 30s or 40s sits firmly in the poor range. It doesn't mean your site is broken, but it does mean visitors are waiting longer than they should, and that's costing you.
One thing the score is not: a direct Google ranking number. Google doesn't take your Lighthouse score and plug it into the ranking algorithm. What it does use are the technical signals that a low score reflects: slow load times, missing mobile support, poor crawlability. The score is a proxy for those signals, not the signal itself. Two sites with identical scores can also have completely different underlying problems, which is why the score alone isn't enough to tell you what to fix.
The four scores the grader shows
Performance measures how fast your site loads. This is the one that most directly affects whether a visitor stays or leaves. It accounts for how long the browser takes to start showing content, how long until the main content is visible, and how stable the page is while it loads. A low Performance score means your visitors are waiting.
SEO measures whether Google can read and index your pages properly. It checks for things like title tags, meta descriptions, and whether your pages are set up to be crawled at all. A site can load quickly and still have a poor SEO score because of missing or misconfigured metadata. Good SEO signals tell Google what your page is about and who it should show it to.
Mobile measures how well the site works on a phone. This covers whether text is readable without zooming, whether buttons are far enough apart to tap accurately, and whether the layout adapts to a small screen. Since most local search happens on mobile, this score has a direct connection to whether people actually use your site when they find it.
Best Practices and Security covers the technical hygiene of the site: whether it runs on HTTPS, whether there are known browser vulnerabilities in the code, and whether the site behaves consistently across different browsers. These issues are less visible to the average visitor but matter for trust signals and for how reliably the site functions.
Why sites are slow: the common culprits
Uncompressed images are the single most common problem on small business websites. A photo straight off a camera or phone can easily be 3 to 5 megabytes. The same image, properly compressed and resized for the web, can be under 200 kilobytes with no visible quality difference. Every uncompressed image the browser has to download adds seconds to the load time.
Too many scripts loading is the second most common issue. Every plugin, booking widget, analytics tool, social share button, and live chat window adds code that the browser has to download and run before the page is ready. Most sites have accumulated these over time, and many of them serve little purpose. The browser doesn't care whether a script is useful. It just waits for it.
No caching means the server rebuilds the page from scratch every time someone visits. Caching stores a ready-made version so the server can deliver it immediately to the next visitor. Without it, every page load starts from zero. For sites on basic content management systems, caching is often either missing or switched off by default.
Slow hosting is an underestimated factor. The cheapest shared hosting plans put your site on a server alongside hundreds or thousands of other sites. When those other sites are busy, your site slows down regardless of how well it's built. The server's response time is the foundation everything else sits on. A slow foundation makes every other problem worse.
What a slow site actually costs you
The immediate impact isn't ranking. It's the visitor who arrived and left before the page finished loading.
Google and SOASTA research from 2017 found that 53% of mobile visitors abandon a page that takes more than three seconds to load. That figure is now several years old and the absolute threshold may have shifted, but the direction hasn't: slower pages lose more visitors, and the drop-off is steep, not gradual.
For a local business, this hits particularly hard. The majority of local searches happen on mobile, often when someone is out and actively looking for a service nearby. If your page doesn't load quickly, they don't wait. They go back to the search results and click the next result. That next result is a competitor.
The ranking effect compounds this. A slow site means some visitors leave immediately, which is a negative behavioural signal. A poorly structured site means Google may not understand what you do or where you operate. Both reduce the likelihood of appearing in front of the right people in the first place.
The two numbers to focus on first
A full Lighthouse report contains dozens of individual metrics and sub-scores. Most small business sites don't need to worry about all of them. Two numbers tell you most of what you need to know at the outset.
LCP (Largest Contentful Paint) measures how long it takes for the main content on the page to become visible. That's usually a headline, a hero image, or a block of text. Google's thresholds: under 2.5 seconds is good, 2.5 to 4 seconds needs improvement, over 4 seconds is poor. LCP is the single clearest indicator of whether visitors are experiencing a fast or a slow site. It's also one of Google's Core Web Vitals, the set of speed metrics that feed most directly into ranking signals.
Overall Performance score gives you the headline view. Combined with LCP, it tells you how serious the problem is and how urgently it needs attention.
Everything else in the report: individual audit items, render-blocking resources, unused CSS, third-party cookie notices, is important context for whoever is doing the fixing. At the diagnostic stage, don't let the detail paralyse you. The two numbers above give you enough to make a decision about what to do next.
What to do with your score
If your Performance or SEO score is under 70, something specific is holding the site back. The free grader gives you the headline scores. The full audit identifies exactly what the problems are and, more importantly, which ones to address first.
If you're in the 70 to 89 range, the site has a workable foundation. You're not in urgent trouble, but there are specific fixes that will make a measurable difference. The audit tells you which ones. Not all improvements have equal impact, and knowing which ones move the needle is what makes the work worth doing.
If you're scoring 90 or above on Performance, check the SEO score too before concluding everything is fine. A fast site with poor SEO signals still doesn't rank. Speed and discoverability are separate problems that can exist independently. A site can load in under a second and still be effectively invisible in search because the metadata is thin, the page titles are generic, or the content doesn't signal what the business does and where it does it.
The score gives you a starting point. What you do with it determines whether it stays where it is or improves.