Speed is money: what every second costs you in sales

Speed is not a technical detail. It is a percentage of your revenue. Measurements on online stores show the same thing over and over: every second added to load time costs a measurable share of the business, and the effect is sharpest in the first three seconds.

On a phone it is harsher still. People who are waiting are not patient. They go back and tap the next result, which is your competitor.

Measure it properly

The most common mistake is judging speed by opening your own site on your own computer. Your browser has everything cached and you are on the best connection you own.

1. Use PageSpeed Insights and read the mobile number, not the desktop one.
2. Test on your own phone outdoors on 4G, not on your home network.
3. Test in a private window so nothing is cached in advance.
4. Test more than the front page. Product and service pages are often much heavier.

What slows Icelandic websites down, in order

1. Images. A five megabyte photograph displayed at 600 pixels wide is by far the most common cause. The fix: the right size and a modern format like webp.
2. Too many plugins. A CMS with twenty five plugins loads twenty five helpings of extra code.
3. Videos that autoplay at the top of the page.
4. Fonts. Four typefaces in six weights is half a megabyte of nothing.
5. Tracking scripts. Every analytics tool adds requests and waiting.
6. Cheap hosting that responds slowly. You see this as a long wait before anything appears at all.

Three numbers that matter

The third number is the one people feel most without knowing what to call it. When you go to press a button and the page shifts under your finger, that is CLS.

What you fix first

Start with the images. That is the cheapest and most effective move on almost every website. Then take the fonts, then the plugins, and the hosting last.

For reference: the site you are reading paints its first content in under half a second on a phone. That is not magic, it is discipline about every single file that gets sent.

Frequently asked questions