Site speed was treated as a technical detail for a long time. Today it is a commercial one: slow pages lose visitors and fall behind in search results. The effect is felt most acutely by mobile users on weak connections.
Visitors have very little tolerance for waiting before a page appears. A page that does not load is abandoned, and most people who abandon do not return. That affects not just the visit but how the search engine assesses your page.
Looking at a single number in seconds is misleading. Track three things separately:
Always measure on mobile and on a weak connection. Every site is fast on office wifi.
On most sites images make up the bulk of page weight, and that is where the fastest win sits. Do three things: convert to modern formats, serve them at the size they will actually display, and lazy-load anything below the fold. The main image in the first screen is the exception — prioritise it rather than delaying it.
Tracking codes, chat widgets and tools that were trialled and forgotten accumulate over the years. Each one delays loading. List them and remove what is genuinely unused. This is usually the largest gain available at zero cost.
Loading many typefaces and weights delays text appearing. Stay within two families and only the weights you actually use.
Letting unchanged files persist in the browser makes a visible difference on repeat visits. Be careful with frequently updated files, though, or your changes will never reach users.
That last step matters: an improvement made without measurement is a guess, not an improvement. Record the before and after so you know what actually worked.
On most sites images account for the bulk of page weight, which is why starting here delivers the most visible result in the shortest time.
List the images on your highest-traffic pages with their file sizes. Usually a handful of very large files account for most of the weight. Prioritise those.
Measure the area the image actually occupies on screen. A very high-resolution file shown in a small area gives the browser work for nothing. Prepare each image at the size it will be used.
Modern image formats deliver the same visual quality in a substantially smaller file. Check the results visually after conversion; when compression is pushed too far, flat colour areas are the first to degrade.
The main image in the first screen should load with priority, while images below the fold should be deferred. Confusing these two is a frequent mistake: delaying the hero image extends how long the page appears blank.
Write down the numbers before and after. That record demonstrates the value of the work and tells you where to look during the next round.
Tracking codes, chat widgets, heat-mapping tools and plugins that were trialled and forgotten pile up over the years. Each one delays page load, and in most cases nobody ever reviews the list.
Write down every externally loaded script running on your site. For each, answer three questions: what does it do, when was its data last looked at, and what would we lose by removing it?
The answer to the third is often nothing. Tools trialled once and then forgotten exist on almost every site.
It is common to find two separate analytics tools running simultaneously. Both slow the page, while decisions are made from only one. Removing one is a direct win.
Scripts that must stay can often be prevented from blocking the page. Code that loads after the content becomes visible does not affect the user's experience.
Run this audit once a year. New scripts are usually added for a good reason; the problem is that they are not removed when the reason disappears.
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