Core Web Vitals: what to fix first

Core Web Vitals measure how fast your main content appears, how quickly the page responds to input, and how stable the layout is while loading. They affect both search visibility and conversion. Here's where we look first.

Largest Contentful Paint (LCP)

LCP measures when the biggest visible element, often a hero image or headline, finishes rendering. Aim for under 2.5 seconds.

• Serve the hero image in WebP or AVIF, at the size it's displayed
• Don't lazy-load the hero image, and give it high fetch priority
• Preconnect to critical third-party origins such as font providers
• Reduce render-blocking CSS and JavaScript
• Use good hosting and a CDN to cut server response time

Interaction to Next Paint (INP)

INP measures how quickly the page responds when someone taps or clicks. Aim for under 200 milliseconds. Heavy JavaScript is the usual cause of poor scores.

• Remove unused scripts, plugins and tag manager tags
• Delay non-essential third-party scripts until after load
• Break up long JavaScript tasks
• Avoid large client-side frameworks where plain HTML would do

Cumulative Layout Shift (CLS)

CLS measures how much content jumps around as the page loads. Aim for under 0.1.

• Set width and height on images and video
• Reserve space for embeds, ads and banners
• Use font-display swap and matching fallback fonts
• Avoid inserting content above existing content after load

Measure with real user data

Lab tools such as Lighthouse are useful for debugging, but Google uses field data from real visitors. Check the Core Web Vitals report in Search Console and the Chrome UX Report to see what your users experience.

Fix the worst template first, usually the homepage or a high-traffic landing page, then work through the rest of the site.