A slow website costs you visitors before they've read a word. Most of what makes a site fast or slow comes down to a handful of things, and none of them needs a technical background to understand.
1. How much has to be downloaded
Every page is a bundle of files: the page itself, a stylesheet, scripts, fonts and images. The more there is, and the more separate files it's split across, the longer a phone on a mobile signal takes to fetch it. Websites built with page builders and many plugins often load code for features the page doesn't even use.
2. Images
Images are usually the heaviest part of a page. Three things make a big difference:
- Size: a photo shown 400 pixels wide on a phone doesn't need to be 4,000 pixels wide. Good sites keep several copies and let the browser pick the right one for the screen.
- Format: modern formats such as WebP are usually much smaller than JPEG or PNG at the same quality.
- Timing: images further down the page can wait until the visitor scrolls towards them. This is called lazy loading.
3. Fonts
Custom fonts look good but have to be downloaded. A site that uses one well-chosen font file, hosted alongside the site and limited to the characters it needs, avoids extra requests to other servers and shows text straight away while the font arrives.
4. Scripts
Scripts add interaction: menus, forms, chat widgets and tracking. They can also block the page from appearing or responding while they run. Each third-party script, such as a chat or advertising tag, adds another server to wait for. Fewer, smaller scripts, loaded after the page appears, keep things quick.
5. Work done on every visit
Many websites build each page from a database every time someone visits. That takes time, and it gets slower when the server is busy. A static website builds every page once, in advance, and simply sends the finished file. There's less to wait for and less to go wrong.
How to check your own site
Google's free PageSpeed Insights tool tests a page on a simulated phone and a desktop and scores performance, accessibility, best practice and search basics out of 100. Test your home page and one inner page, and look at the mobile score first, because that's how most visitors arrive.
Speed is one part of a good website. Clear content, a page that works with a keyboard and a screen reader, and a form that actually reaches you matter just as much.