Why your website is slow, and what it costs you
In short
A slow site loses customers before it has been read. In the vast majority of cases the cause is not hosting but three things — oversized images, too many third-party scripts, and render-blocking fonts. Measure with PageSpeed Insights first, fix those three, and you will recover most of the lost ground.
A site that takes four seconds to render does not have a technical problem. It has a commercial one, which the original quote probably did not price.
What slowness actually costs
The direct ranking effect is real but modest: speed is one of many Google signals, through Core Web Vitals.
The indirect effect is far more violent. A visitor arriving on their phone, in a waiting room, on three bars of signal, does not wait four seconds. They go back and click your competitor. They will never appear in your conversion statistics, because they never saw your page.
That is what makes the problem insidious: slowness does not show up in your numbers, it shows up in the numbers you do not have.
Measure before touching anything
Open PageSpeed Insights and test your homepage. Look at three things, in this order:
- The mobile score, not the desktop one. Mobile is what counts.
- Largest Contentful Paint: how long until the biggest visible element appears. Target under 2.5 seconds.
- Cumulative Layout Shift: how much the page jumps while loading. Target under 0.1.
Test an article page and a service page too — they often have different problems from the homepage.
The three causes, in order of frequency
Images
By far the leading cause. A photo taken on a phone is 4 MB. Displayed in a 600-pixel-wide block, it should be 60 KB — seventy times smaller.
What to do: resize to the dimensions actually displayed, convert to WebP or AVIF, and lazy-load everything below the fold. On a modern stack the tooling does this automatically. On an older site it is often an afternoon of work for a dramatic gain.
Third-party scripts
Every tool added to the site — cookie banner, live chat, ad pixel, interactive map, review widget, external font — adds one or more requests to a server you do not control.
A business site easily accumulates ten of them. Open your browser's Network tab and look at the list. The question for each line: what did this tool earn me this month?
The live chat nobody uses costs 300 KB and half a second. That is not a good trade.
Fonts
A font loaded from an external service adds a connection before text can render. Depending on configuration, the visitor sees either blank space or text that changes shape mid-load — which also damages Cumulative Layout Shift.
The fix is simple: host the font with the rest of the site, serve it as WOFF2, and ship only the weights you actually use. Two weights are nearly always enough.
What is probably not the problem
Your host. Unless it is genuinely bad, server response time is a fraction of the total on a marketing site. Changing hosting to fix an image problem is repainting a room to fix a leak.
Your CMS. WordPress is not inherently slow. WordPress with forty plugins and a purchased theme that loads twelve more, yes. The problem is accumulation, not the tool.
Where to start
Deal with images, remove third-party scripts whose benefit you cannot name, self-host your fonts. Those three actions solve most cases and require no rebuild.
Measure again after each change, one at a time. It is the only way to know which one paid — and if you are about to commission a rebuild, it is also the best argument for demanding a written performance commitment in the quote.
Frequently asked questions
What load time should a website target?
Aim for a Largest Contentful Paint under 2.5 seconds on mobile over 4G, and a mobile PageSpeed Insights score above 90. That is achievable for a standard marketing site, provided images and third-party scripts are dealt with.
Does Google penalise slow websites?
Yes, speed is a ranking signal through Core Web Vitals, but the direct effect is modest. The indirect effect is far stronger — a visitor who leaves before the page renders does not read, does not convert, and their behaviour degrades your engagement signals.
Will changing hosting provider speed up my site?
Rarely, unless your current hosting is genuinely bad. On a marketing site, time is spent downloading images and executing JavaScript, not waiting on the server. Measure before you switch.
How can I measure my site speed for free?
Use Google PageSpeed Insights. It gives both lab measurements and, if your site has enough traffic, real data from your Chrome visitors. Always test the mobile version first- that is the one that counts for ranking.