Speed affects both rankings and conversions, and the causes are boringly consistent. In almost every slow site we audit, the same three things account for most of the problem, and images are nearly always the largest of them.
Images, which are usually most of the problem
Full-resolution photography uploaded straight from a phone or camera is the single most common cause of a slow website. A three-megabyte image displayed at 800 pixels wide is wasting the overwhelming majority of what it downloads.
- Resize images to the dimensions they actually display at
- Use modern formats like WebP, which are substantially smaller at the same visible quality
- Enable lazy loading so images below the fold load only when needed
- Compress — most photos lose nothing visible at 80% quality
Too many plugins and scripts
Every plugin adds code, and many load on every page whether needed or not. Chat widgets, tracking pixels, font libraries and slider plugins are common offenders. Audit what is installed and remove anything not earning its place.
Hosting
Cheap shared hosting is cheap because you are sharing resources with hundreds of other sites. If your site is optimised and still slow, hosting is often the remaining constraint. This is usually the least glamorous and most effective fix available.
Caching
Caching serves a pre-built version of the page instead of assembling it on every visit. Most platforms have a caching option and many sites simply have not enabled it. It is typically a large improvement for very little effort.
How to measure it properly
Use Google PageSpeed Insights and look at the field data rather than the lab score if it is available, because that reflects what real visitors experienced. Chasing a perfect score is not worth it; getting into the green on Core Web Vitals is.
Frequently asked questions
Why is my website so slow?
Most commonly unoptimised images, followed by too many plugins and scripts, then hosting. Check them in that order.
Does site speed affect SEO?
Yes. Core Web Vitals are a ranking factor, and speed also affects conversion — slow pages lose visitors before they see anything.
What is a good page load time?
Under two and a half seconds for the largest content element is the Core Web Vitals threshold. Faster is better, but that is the target to clear.
Will a new theme fix my slow website?
Sometimes, but if the cause is unoptimised images or bad hosting a new theme changes nothing. Diagnose before rebuilding.
Related reading
Related: 9 signs you need a website redesign, What website automation costs
Worth reading: What lead generation costs, What is marketing automation?
Get in touch
If you want an honest view on your own situation, tell us what your website is meant to do and what it is doing instead. We will come back within one business day.