Website speed affects both SEO and conversions directly. Google measures loading speed, responsiveness, and visual stability through Core Web Vitals and factors them into rankings, while slow-loading pages independently cause visitors to leave before they ever see your content. Unoptimised images, bloated themes and plugins, and render-blocking scripts are the most common causes on Christchurch business websites.
A slow website costs you twice. Google measures how quickly a page loads, responds and settles down, and visitors who wait on a slow page often head back to the results and try the next business instead. The good news is that you can see exactly what is slow, for free, in about ten minutes.
How Google measures speed
Google's Core Web Vitals documentation sets out three measures, each with a published target:
- Largest Contentful Paint (LCP): how long until the main content, usually a big image or headline, is visible. Target: 2.5 seconds or under.
- Interaction to Next Paint (INP): how quickly the page responds when someone taps or clicks. Target: 200 milliseconds or under.
- Cumulative Layout Shift (CLS): how much the page jumps around while loading. Target: 0.1 or under.
A page counts as good when at least 75 percent of real visits meet the target, according to that documentation. Speed is one input among many, and a quick site with weak content will not outrank a slower one that answers the search better. But a slow site holds back everything else you do, which is why it is on our technical SEO checklist.
Read your results properly
Paste your homepage into PageSpeed Insights and select the mobile tab. You will see two kinds of data, and they are not the same thing.
Field data comes from real Chrome users visiting your site over the previous 28 days. This is what Google uses, so it matters most. Small local sites often show "not enough data", which is normal and not a fault.
Lab data is a simulated test run on one device and connection at one moment. It is useful for finding causes and checking fixes, but the score can wobble between runs. Do not chase a perfect 100. Chase the specific items listed under Opportunities and Diagnostics.
Search Console has a Core Web Vitals report too, which groups your pages into good, needs improvement and poor, so you can see whether a problem is sitewide or limited to one template.
The usual causes, and what to do about each
Slow loading (LCP)
Large images are the usual cause. Say an Addington cafe uploads a 5MB photo of its flat whites as the homepage banner. The fix is to resize it to the size it is displayed, compress it, and use a modern format such as WebP if your platform supports it. One caution: do not lazy-load the main banner image. Lazy loading suits images further down the page, but deferring the one the visitor sees first makes LCP worse.
Sluggish response (INP)
Heavy scripts are the cause here, and the biggest offenders are often third-party: chat widgets, booking pop-ups, tracking tags and sliders. Each one competes for the phone's processor. List everything the site loads, and ask of each: does this earn its place? Remove what is not used.
Jumping layout (CLS)
You have seen this: you go to tap a button and the page lurches as an image or cookie banner loads above it. Common causes are images without set dimensions, banners that push content down, and web fonts that swap in late. Giving images fixed width and height, and reserving space for banners, fixes most of it.
Slow server and no caching
If the server takes a long time to start sending the page, no image trick will rescue it. Cheap shared hosting and a lack of caching are the usual reasons. A caching plugin or a better hosting plan is worth testing before you think about a rebuild.
A quick way to put this into practice: run the homepage and your busiest service page, note the three numbers for each on mobile, and save a screenshot. Make one change, wait for the cache to clear, run both again and compare. Keeping a simple before-and-after record stops you guessing about what worked.
Where to spend your effort first
Start with images, because the effort is low and the effect is often large. Next, remove scripts and plugins you do not use. Then address layout shift. Hosting and theme problems come last, since they cost more and are riskier to change. Test after each change so you know what helped. A Hornby plumber with a gallery of van and job photos, a chat widget and a booking embed might clear most of the problem with the photos alone.
Be honest about the limits. Speed work will not fix thin content or a missing Business Profile, and the figures only update after enough real visits. If you run a shop, speed matters even more, because every extra second sits between a customer and the checkout; SEO for Christchurch online stores looks at that.
If speed was part of a drop
Speed problems rarely cause a sudden collapse. They are more likely a slow drag. But if your rankings fell soon after a redesign or a new plugin, test the page before and after. Our guide on recovering from a ranking drop explains how to tell if speed is the cause or a coincidence. Slow speed also sits alongside other issues in the five most common mistakes on Christchurch business sites.
If you want the findings explained and prioritised for your own site, our SEO audit service covers Core Web Vitals page by page. For a quick first look, request a free SEO review and we will tell you whether speed is worth fixing first.
