Core Web Vitals for small sites: a practical checklist
Google’s three thresholds, four things to do and three to stop doing, and how to measure what your visitors actually get.
Core Web Vitals are three measures Google uses to describe how a page feels to load and use: how fast the main content shows, how quickly the page reacts, and how much it jumps around. For a typical small site, meeting them comes down to a handful of fixable habits. Here are the thresholds, then the checklist to run before any launch.
| Measure | What it measures | Good at or under |
|---|---|---|
| Largest Contentful Paint (LCP) | Loading of the main content | 2.5 seconds |
| Interaction to Next Paint (INP) | Reaction to clicks and taps | 200 milliseconds |
| Cumulative Layout Shift (CLS) | Visual stability | 0.1 |
Do these
- Serve images in modern formats and size them to their container.
- Set explicit width and height on images to stop layout shift.
- Preload the one font and the hero image that matter, lazy-load the rest.
- Ship less JavaScript: every script is a tax on the main thread.
Stop doing these
- Loading five tracking scripts before the page is even visible.
- Embedding a heavy map or video that nobody scrolls to.
- Shipping a 4000px hero image to a phone.
To find which pages are slow across a whole site, a site audit tool crawls every page and lists the heavy images and scripts.
Every item on this list is part of how we approach web development, and the measuring tools are in the tool reviews.