Google's Core Web Vitals get discussed as a ranking factor, which is true but beside the point. The reason to care is simpler: a large share of your visitors are on a phone, on cellular, possibly in a parking lot. If your homepage takes six seconds, a third of them are gone before it appears.

The three metrics, in plain terms

  • LCP — how long until the biggest thing on screen appears. Usually your hero image or headline. Target under 2.5 seconds.
  • CLS — how much the page jumps around while loading. This is the one where you go to tap a button and an ad shoves it sideways. Target under 0.1.
  • INP — how quickly the page responds when you actually interact. Target under 200ms.

What's usually to blame

Images, almost always. A 4MB photo straight off a phone, dropped into a page and scaled down with CSS. The browser still downloads all 4MB. Resizing to the size it actually displays and serving modern formats routinely cuts page weight by 80%.

Too many third-party scripts. Analytics, a chat widget, a heat map, two pixels, a review carousel, a booking embed. Each is small. Together they're the majority of your load time and most of your INP problem.

Fonts. Custom web fonts block text from rendering, then swap and shift the layout. Limiting to two weights and preloading fixes most of it.

No dimensions on images. Without width and height, the browser doesn't reserve space, so everything below jumps when the image lands. That's most CLS problems in one line of markup.

The seasonal angle

Businesses here get concentrated traffic bursts — tourist season, event weekends, the days after a storm. Those are exactly when marginal hosting falls over. A site that's merely sluggish on a slow Tuesday becomes unusable on the day you most need it.

How to actually check

Run PageSpeed Insights, but read the field data at the top — that's real visitors on real devices. The lab score below it is a simulation on a fast machine and is much more flattering than reality.

Search Console has a Core Web Vitals report showing which URL groups fail across your whole site, which is more useful than testing pages one at a time.

The short version

Compress the images. Remove the scripts you're not using. Set width and height on images. That's the majority of the gain for most small business sites, and none of it requires a rebuild.