Google's own research shows that 53% of mobile site visits are abandoned when pages take more than 3 seconds to load. For an e-commerce site doing £10,000/month in revenue, even a 1-second delay in load time can cost you hundreds of pounds every month in lost conversions.
Here's what's typically causing slowness — and what you can do about it.
The Problem: What Slows Sites Down
Unoptimised Images
Images account for the majority of page weight on most websites. A single uncompressed hero image can be 2–5MB — easily taking 3–5 seconds to load on a mobile connection. The fix is simple: compress images, use modern formats (WebP or AVIF), and use proper sizing so images are never loaded larger than they're displayed.
Too Many Plugins and Third-Party Scripts
Every plugin, chat widget, analytics script, and marketing tag that loads on your page adds load time. Audit what's actually necessary — you'd be surprised how many sites are loading 20+ third-party scripts they no longer use.
No Caching
Without caching, your server builds each page from scratch for every visitor. With a caching layer (browser caching + a server-side cache), returning visitors and even first-time visitors on CDN edge nodes get your page in milliseconds rather than seconds.
Cheap Hosting
Shared hosting on a crowded server is often the root cause of slow sites. If your server response time (Time to First Byte) is over 600ms, your hosting is likely the bottleneck — no amount of optimisation will fully fix a slow server.
Render-Blocking JavaScript and CSS
Scripts and stylesheets loaded in the wrong order prevent the browser from displaying anything until they've fully downloaded and parsed. This increases Largest Contentful Paint (LCP), a core ranking signal.
Core Web Vitals: What Google Measures
Google uses three specific metrics to assess page experience:
- Largest Contentful Paint (LCP): How long until the main content is visible. Target: under 2.5 seconds.
- Interaction to Next Paint (INP): How quickly the page responds to user input. Target: under 200ms.
- Cumulative Layout Shift (CLS): How much the layout jumps around as it loads. Target: under 0.1.
Poor scores in any of these can suppress your search rankings — Google introduced these as a direct ranking factor in 2021.
How to Fix It
Step 1: Benchmark with PageSpeed Insights
Go to pagespeed.web.dev, enter your URL, and run the test for both mobile and desktop. The report will highlight your biggest issues with specific recommendations.
Step 2: Compress and Modernise Your Images
Use Squoosh, ShortPixel, or Cloudinary to compress images and convert them to WebP. Implement lazy loading so images below the fold don't load until they're needed.
Step 3: Implement Caching
On WordPress, a plugin like WP Rocket or LiteSpeed Cache adds server-side page caching and browser caching headers. On other platforms, your host should offer caching — or a CDN like Cloudflare can be added for free.
Step 4: Defer Non-Critical Scripts
Add defer or async attributes to JavaScript that doesn't need to load before your page renders. Move scripts to the footer where possible.
Step 5: Upgrade Your Hosting
If your Time to First Byte is consistently over 600ms, it's time to move to a faster host. Managed WordPress hosts and cloud platforms like Vercel or Cloudflare Pages deliver dramatically faster TTFB.
The Business Case
Shopify published data showing that a 10% improvement in page speed increases conversion rate by 7%. For most sites, getting from a 4-second load to a 2-second load is achievable with a weekend of work — and the revenue impact can be significant and permanent.
Need help speeding up your site? Our Website Audit service includes a full Core Web Vitals review and a prioritised fix list.