The numbers that matter
'Load time' as one number is misleading, because a page can show its content quickly while still downloading things in the background. Google measures three moments instead, called Core Web Vitals: how soon the biggest visible element appears (Largest Contentful Paint, good is 2.5 seconds or less), how quickly the page responds to a tap (Interaction to Next Paint, good is 200 milliseconds or less), and whether things jump around as the page loads (Cumulative Layout Shift, good is 0.1 or less). These are measured from real visitors on real phones, not from a fast office computer.
Why speed is worth money
- Visitors leave. Studies from Google and others have consistently found that the share of visitors who abandon a page climbs steeply as load time passes three seconds, and that is on top of visitors who never see the page because it ranked lower.
- Rankings. Core Web Vitals are a ranking factor. A small one compared to content and relevance, but it decides ties between similar pages.
- Conversions. Faster pages convert better in nearly every published test, because fewer people give up partway through a form or a checkout.
- Ads. If you run Google Ads, slow landing pages lower your quality score and raise what you pay per click.
What makes sites slow, and what fixes it
In rough order: images uploaded straight from a camera or phone at full size; themes and page builders that load every feature on every page; too many plugins and third-party scripts (chat widgets, trackers, embedded video); fonts loaded from several places; and cheap shared hosting. The fixes, in the same order: compress and resize images and serve them in modern formats, drop the builder or trim it, remove scripts you do not need, limit fonts, add caching and a CDN, and move to decent hosting. The page on slow websites goes through each with examples. Check your own numbers in PageSpeed Insights; see how to check whether your website is mobile friendly.