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Website Performance

Why Your Website Is Slow — And What's Actually Causing It

A slow website doesn't just feel frustrating — it actively costs you visitors. Most people abandon a page that takes more than 3 seconds to load. Here's what's actually behind that, and what to fix first.

Zoli Sabo

Zoli Sabo

4 Jun 2025 · 7 min read

When I run a website audit for a local business, a performance score below 50 is one of the most common findings. And the causes are almost always the same — not because businesses are doing anything wrong, but because websites accumulate problems over time and nobody is watching.

A WordPress site that was reasonably fast three years ago can score below 40 today — not because anything was deliberately changed, but because plugins were added, images were uploaded at full resolution, and the hosting environment stayed the same while everything else moved on.

What PageSpeed Score Actually Means

Google's PageSpeed Insights scores your website from 0 to 100 on both mobile and desktop. The mobile score is what matters most for local businesses — the majority of local searches happen on phones, and Google uses mobile performance as a ranking signal.

90–100

Good — fast enough that users rarely notice

50–89

Needs work — some visitors will leave before it loads

0–49

Poor — a significant portion of visitors are leaving

The Most Common Causes — In Order of Impact

1. Unoptimised images

This is the single biggest cause of slow local business websites. A photo taken on a modern phone is typically 3-8MB. Uploaded directly to WordPress without compression, it sits there loading every time someone visits the page.

A properly optimised version of the same image should be under 200KB — that's a 15-40x size reduction with no visible quality difference on screen. Multiply this across 10-20 images on a typical business website and you start to understand why the page takes 8 seconds to load on mobile.

Fix

Before uploading any image to your website, compress it first using Squoosh (squoosh.app — free, in-browser) or TinyPNG. For existing images on WordPress, the plugin Imagify or ShortPixel can compress your entire media library in one go. Use WebP format where possible — it's 25-35% smaller than JPEG at equivalent quality.

2. Too many plugins — especially inactive or outdated ones

WordPress plugins add functionality — but each one adds code that has to load every time a page is requested. A site with 25 plugins, half of which are barely used, is loading the equivalent of 25 small applications for every visitor.

Outdated plugins compound this in two ways. First, older code is often less efficient than modern equivalents. Second, unpatched plugins are a known security vulnerability — they're one of the most common entry points for website hacks. A slow, insecure plugin is the worst of both worlds.

When I audit WordPress sites, it's common to find 20-30 plugins installed, with 5-10 that are either inactive, duplicating functionality, or haven't been updated in over a year.

Fix

Go to WordPress → Plugins → Installed Plugins. Deactivate and delete anything you don't actively use. Update everything that remains. If two plugins do similar things (e.g. two SEO plugins, two caching plugins), keep one and remove the other.

3. CSS and JavaScript not minified or combined

Every plugin and theme typically loads its own CSS and JavaScript files. A WordPress site with 15 plugins might be loading 30-40 separate files before the page even starts to display. Each file is a separate request to the server — and each request adds time.

Minification removes unnecessary spaces, line breaks, and comments from code files to reduce their size. Combining files reduces the number of server requests. Both are standard optimisations that make a measurable difference — and neither requires changing how the website looks or functions.

Fix

Install a caching and optimisation plugin such as WP Rocket, LiteSpeed Cache (if your host supports it), or W3 Total Cache. These handle minification, file combining, and browser caching automatically. Run PageSpeed before and after to see the difference.

4. Hosting that was cheap five years ago

Shared hosting — where your website shares a server with hundreds of other websites — is fine for low-traffic sites. But as your site grows, or if a neighbour on the shared server gets a traffic spike, your site slows down.

Server response time (also called TTFB — Time to First Byte) should be under 200ms. If it's above 600ms, the hosting itself is the bottleneck — and no amount of image compression or plugin removal will fully fix it. Upgrading to a better shared plan, a VPS, or a host with faster infrastructure is the solution.

Fix

Check your TTFB in PageSpeed Insights under "Server response time." If it's consistently above 500ms across multiple tests, consider switching hosts. Siteground, Kinsta, or Cloudways are solid options for WordPress sites that need reliable performance.

Check your score right now

You can run a free performance scan on your website in about 30 seconds. It checks your PageSpeed score, identifies the top issues, and tells you what to fix first — no sign-up required.

Run a free website scan →

Want someone to fix it properly?

Performance issues are part of every website audit I do. I identify exactly what's causing the slowdown, prioritise what will have the biggest impact, and either advise on fixes or implement them directly.

Book a free audit call →
Zoli Sabo

Zoli Sabo

Digital marketing auditor working with local service businesses across the EU, UK, and Australia.