Key takeaways
- Large images, heavy themes, too many plugins and weak hosting are the most common causes of slow websites.
- Google measures loading, responsiveness and visual stability through Core Web Vitals.
- Test your site with PageSpeed Insights, fix the biggest issues first and retest.
Website speed affects everything: how long visitors stay, how many enquiries you receive and how well you rank on Google. The good news is that most slow websites can be made much faster with a few focused improvements.
Why website speed matters
- Visitors leave slow pages: especially on mobile data, people will not wait.
- Google uses page experience signals: speed and stability are part of how pages are evaluated.
- Faster sites convert better: less waiting means more calls, messages and sales.
Understand Core Web Vitals
Google measures real user experience with three Core Web Vitals:
- Largest Contentful Paint (LCP): how quickly the main content appears. Aim for 2.5 seconds or less.
- Interaction to Next Paint (INP): how quickly the page responds to taps and clicks. Aim for 200 milliseconds or less.
- Cumulative Layout Shift (CLS): how stable the page is while loading. Aim for 0.1 or less.
You can check these for free with Google PageSpeed Insights.
1. Optimise your images
Images are usually the biggest cause of slow pages. Resize images to the size they are displayed, compress them and use modern formats like WebP. Lazy load images below the fold so they load only when needed.
2. Choose good hosting
Cheap, overcrowded hosting can slow every page. Choose hosting with good server performance and a data centre close to your customers. Read web hosting explained.
3. Use caching
Caching stores ready made versions of your pages so they load faster for returning visitors. On WordPress, a good caching plugin makes a big difference.
4. Reduce plugins and heavy scripts
Every plugin, font and tracking script adds weight. Remove what you do not use. Replace heavy page builders and sliders with lighter alternatives where possible.
5. Use a lightweight theme or clean code
Some themes load lots of code you never use. A lightweight theme or a clean custom build keeps pages lean. Compare options in WordPress versus custom website.
6. Minify and combine files
Minifying CSS and JavaScript removes unnecessary characters, making files smaller. Loading only what each page needs helps even more.
7. Use a content delivery network
A CDN serves your files from locations closer to your visitors, which helps if your customers are spread across cities or countries.
8. Keep everything updated
Updates often include performance improvements. Regular website maintenance keeps your site fast over time.
Tip: fix the biggest issues first. Compressing a few large images often improves speed more than dozens of small tweaks.
How to test your website speed
- Open Google PageSpeed Insights and enter your page address.
- Look at both the mobile and desktop results, focusing on mobile.
- Check the Core Web Vitals and the main opportunities listed.
- Test your most important pages, not only the home page.
- Also test on a real phone using mobile data.
Scores can vary slightly each time you test, so look at trends and the biggest issues rather than chasing a perfect number.
A speed checklist you can follow
- Resize and compress all large images
- Convert images to modern formats like WebP
- Lazy load images and videos below the first screen
- Remove unused plugins, fonts and scripts
- Enable caching and compression on the server
- Limit heavy sliders, animations and autoplay videos
- Load only the fonts and weights you actually use
- Use good hosting close to your customers
Tip: third party widgets such as chat tools, review feeds and social embeds often slow pages. Keep only the ones that clearly help your business.
Speed and online stores
Online stores need extra attention because product pages often have many images and extra features. Optimise product photos, use caching carefully so carts and checkout still work correctly, and test category pages with many products. A faster store usually means more completed orders. See our ecommerce launch checklist.
Keeping your site fast over time
Websites slow down gradually as new images, plugins and features are added. Check speed every month, compress new images before uploading and review plugins regularly. Treat speed as ongoing care, just like security and updates.
Quick wins you can do today
If you want fast results, start with these simple steps. Find the five largest images on your home page and compress them. Remove any plugins or widgets you no longer use. Replace an autoplay video at the top of the page with an image and a play button. Check that caching is turned on. These small changes often make a visible difference within an hour, and they give you a faster base before tackling bigger improvements.
Frequently asked questions
What is a good website loading time?
Aim for the main content to appear within about 2.5 seconds, which matches Google's recommended Largest Contentful Paint target.
Does website speed affect SEO?
Yes. Page experience, including speed, is one of many signals Google considers, and faster pages also keep visitors engaged.
Why is my website slow on mobile but fast on desktop?
Phones often have slower connections and less processing power, so heavy images and scripts affect them more. Optimising for mobile helps everyone.
Will a CDN make my website faster?
A content delivery network can help, especially if your visitors are spread across different cities or countries.
Can too many plugins slow my WordPress site?
Yes. Each plugin can add code and requests. Keep only the plugins you need and choose well built ones.
Is it better to rebuild a very slow website?
If a site is built on a heavy, outdated theme, rebuilding it lean can be more effective than many small fixes.
Do images really slow down websites that much?
Often, yes. A single uncompressed photo can be larger than the rest of the page combined, which is why image optimisation is usually the first step.
When to consider a rebuild
If your website is built on an old, heavy theme, a redesign can be faster and cheaper than endless fixes. Every website we build at Web & Growth is optimised for speed from the start. Contact us for a free speed review.
Need Help With Your Website?
Talk to Web & Growth for a free consultation and a clear written quote.
