Why your website is slow and how to speed it up: a checklist

A user leaves a page if it takes too long to appear. And Google takes speed into account when choosing positions. So a slow site loses both visitors and traffic. Below I show how to measure speed, what spoils it most often and where to start.

How to measure

• PageSpeed Insights: a free Google tool. You enter an address and get a score and a list of problems for phone and computer.
• The Core Web Vitals report in Google Search Console: shows real data from your visitors.
• Lighthouse in the Chrome browser: a detailed analysis in the developer tools.

Look at the phone first: most visitors come from it, and the mobile result is usually worse.

Three key metrics

Google calls them Core Web Vitals. The "good" benchmarks:

What most often slows a site down

1. Heavy images

Photos of several megabytes, in an old format and too large. This is the number one cause. The fix: modern formats, sizes matched to the screen, lazy loading for those below the first screen.

2. Fonts

Several external fonts block text from showing. The fix: fewer font weights, self-hosted fonts, loading only the characters you need.

3. Extra scripts

Chat widgets, analytics, ad pixels, sliders: each adds weight. The fix: remove what isn't needed, defer loading the rest.

4. A heavy theme or builder

Ready-made themes and builders pull in a large amount of code you don't use. The fix: slim it down or replace it with your own lightweight markup. For WordPress, more in the article WordPress or custom code.

5. A slow server and no caching

Cheap hosting, no cache, slow database queries. The fix: caching, a CDN, query optimisation, different hosting if needed.

6. Layout shifts

Blocks "jump" because no space was reserved in advance for images and ads. The fix: specify the sizes.

What to do first: a short plan

1. Measure and write down the current figures.
2. Compress and replace the images: a quick and noticeable win.
3. Remove unneeded scripts and widgets.
4. Set up caching.
5. Check the fonts.
6. Measure again and compare.

Often the first three steps give most of the effect.

When deeper work is needed

If the site is still slow after this, the cause lies deeper: outdated code, a bloated architecture, a slow database.

Then it makes sense to do a website speed-up with an audit, or a redesign on a modern stack.

If the site is on WordPress, see also WordPress websites.

Frequently asked questions

What loading speed counts as normal?

Google's benchmark: the main content (LCP) should appear in no more than 2.5 seconds on a phone. The faster, the better.

Does speed affect Google positions?

Speed is taken into account as one of the factors. It won't replace good content, but a slow site loses to a fast one, all else being equal, and also loses customers who didn't wait for it to load.

Can it be sped up without a full rebuild?

Mostly yes. Images, scripts and caching are fixed without rewriting the site.

Website speed-up: terms and what is included.