Website Speed and Core Web Vitals: A Plain-Language Checklist

Website Speed and Core Web Vitals: A Plain-Language Checklist

Core Web Vitals are Google's measures of how a page feels to real visitors. They are one of many ranking signals, and slow, jumpy pages also lose customers.

Last reviewed: November 2026.

The three measures

• Largest Contentful Paint (LCP): how quickly the main content appears. Google's guidance is to aim for 2.5 seconds or less.
• Interaction to Next Paint (INP): how quickly the page responds when someone taps or clicks. Aim for 200 milliseconds or less.
• Cumulative Layout Shift (CLS): how much the page jumps around while loading. Aim for 0.1 or less.

The checklist

1. Compress and size images. Use modern formats, serve the right size for the screen and set width and height so the layout does not shift.
2. Lazy-load images below the fold, but not the main image at the top.
3. Cut unused scripts. Chat widgets, trackers and plugins add up. Remove what you do not use and load the rest after the main content.
4. Use a fast host and a CDN.
5. Load fonts sensibly. Fewer font files, with text shown while fonts load.
6. Reserve space for ads, embeds and banners so they do not push content down.
7. Keep important content in the HTML, so it does not wait for scripts.

How to check

Google Search Console shows Core Web Vitals from real visitors. PageSpeed Insights shows both real-visitor data, when available, and a lab test. Always test on a phone.

How we help

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