Yes, your website speed affects your Google ranking. But here's the thing: it will cost you customers long before it ever costs you positions in search results.
Google made page experience an official ranking signal in 2021. They measure it through something called Core Web Vitals, a set of three specific performance metrics. If your site scores badly on these, it's working against you in the rankings. But the real damage happens before someone even gets to see your content. People leave slow websites. They don't wait. They go back to Google and click the next result.
So even if speed only nudges your ranking slightly, its effect on your conversion rate can be dramatic.
I worked with a professional services firm in Gwynedd whose site was getting reasonable search traffic but almost no enquiries. A PageSpeed audit showed a mobile score of 24. The main culprit was a 4MB hero image above the fold, which meant the page was effectively blank for the first five seconds on a phone. Compressing that image and three others took the score above 70. Enquiries from mobile visitors more than doubled within a month, with no other changes made.
What Core Web Vitals actually are
Google uses three measurements to assess your site's speed and stability. These sound technical, but the concepts are straightforward.
LCP (Largest Contentful Paint) is how long it takes for the biggest visible element on your page to load. Usually that's your hero image or your main headline. Think of it as the moment the page feels loaded. Google wants this to happen within 2.5 seconds. If it's taking 4 or 5 seconds, that's a problem for both rankings and for the person staring at a blank screen.
CLS (Cumulative Layout Shift) measures how much your page jumps around as it loads. You've experienced this: you go to tap a button and the page shifts just as you tap, and you end up clicking something else entirely. That's a high CLS score. Google scores you on a scale of 0 to 1, and anything above 0.1 is considered poor. It sounds minor but it's a genuine annoyance that puts people off.
INP (Interaction to Next Paint) replaced an older metric called FID in 2024. It measures how quickly your page responds when someone interacts with it, clicking a menu, tapping a button, filling in a form. A sluggish response makes a site feel broken even when it isn't. Google's threshold is under 200 milliseconds.
All three feed into your overall page experience score. None of them require you to be a developer to understand, though fixing them sometimes does.
What actually slows a website down
In my experience with small business websites, the causes of slow loading times come down to the same handful of issues time and again.
Unoptimised images are the most common culprit. A photographer or designer hands over images at full resolution and they go straight onto the website. A single image can be 3MB or more. Most website images should be under 200KB and served in a modern format like WebP. If you can see the image is sharp and beautiful but the page takes forever to load, this is almost certainly why.
Bad hosting is the second most common cause. Budget shared hosting is cheap for a reason. Your site shares server resources with hundreds of other sites, and when those sites are busy, yours suffers. Moving to a quality managed hosting provider is often the single biggest performance improvement you can make, and the price difference between poor hosting and good hosting is usually £10-20 a month.
This is probably the most underrated fix in web performance. Business owners focus on design and plugins, but switching from a budget host to a decent managed host can cut server response times by 60-70% with no other changes. I've seen mobile PageSpeed scores jump from the 30s to the 60s purely from a hosting migration.
Too many plugins, particularly on WordPress sites, add weight. Every plugin loads its own scripts and stylesheets. Most WordPress sites I audit have at least a handful of plugins doing things that could be handled more efficiently or not at all. Plugins that load scripts on every page, even pages where they're not used, are especially wasteful.
Theme bloat is the fourth issue. Many off-the-shelf WordPress themes come with enormous amounts of code to support features you'll never use. A theme built for a hotel business includes booking functionality, event management, gallery features, all loading even on a simple text page. Lightweight themes or custom builds avoid this entirely.
How to test your site speed
Google PageSpeed Insights is the tool to use: pagespeed.web.dev. It's free, it takes about 30 seconds, and it tells you your Core Web Vitals score for both mobile and desktop.
Enter your website URL and run the test. Pay attention to the mobile score specifically, because that's where most local search traffic comes from and where scores tend to be lower.
The tool gives you a score out of 100 and a list of specific issues, ordered by impact. You don't need to understand all of them. Look at the top three items under "Opportunities" and "Diagnostics". Those are the things worth fixing first.
A score above 90 is good. Between 50 and 90 means there's room for improvement. Below 50 means your site has real performance problems that are likely costing you visitors.
Practical fixes you can start with
If your images are large, compress and resize them. Tools like Squoosh (free, browser-based) let you compress images without a developer. Swap out the biggest offenders first. If you're on WordPress, a plugin like ShortPixel can automate this going forward.
If your hosting is slow, ask your web developer or hosting provider what your server response time is. If they can't tell you, or if PageSpeed Insights flags "Reduce initial server response time" as a major issue, it's worth looking at alternatives. WP Engine, Kinsta, and SiteGround are all meaningfully faster than generic shared hosting.
If you're running WordPress with a lot of plugins, ask your developer to do a plugin audit. Some will be essential. Others will have been installed to solve a problem years ago and forgotten about. Removing unused plugins reduces load and reduces security risk.
For CLS, the most common fix is adding explicit width and height attributes to images so the browser reserves the right space before the image loads. This sounds minor but makes a noticeable difference to layout stability.
For INP, the fix is usually reducing JavaScript. This is more technical, but your developer can use the "Reduce JavaScript execution time" guidance in PageSpeed Insights to find the worst offenders.
Speed and conversions
Here's the number that usually gets business owners' attention: according to Google's own research, as page load time goes from 1 second to 3 seconds, the probability of a visitor bouncing increases by 32%. From 1 second to 5 seconds, it increases by 90%.
If your website is taking 5 or 6 seconds to load on mobile, roughly half the people who arrive are leaving before they've seen anything. No amount of great content or good Google rankings fixes that.
A faster website converts better, ranks better, and gives a better first impression. It's worth the investment.
If your site is slow and you're not sure where to start, get in touch. I do website reviews for North Wales businesses that cover performance, conversion, and SEO in one go. You can also read more about why visitors aren't getting in touch and how to build a website that actually converts, both of which cover the conversion side of what happens after someone arrives on a slow or fast site.
For the technical side of things, website design and optimisation is one of the core services I offer to businesses across North Wales.
