Core Web Vitals are a set of performance metrics defined by Google to measure how user-friendly your website is—especially when it comes to speed, stability, and responsiveness. In other words, they reflect how your site feels to your visitors.
Google uses these metrics as part of its ranking algorithm. But more importantly, they shape how people experience your site. If it loads slowly, shifts around when you’re trying to click something, or lags during interaction, you’re likely to lose trust and conversions.
What are the three Core Web Vitals?
Each metric focuses on a specific aspect of user experience:
- Largest Contentful Paint (LCP)
Measures how long it takes the main content of a page to load (usually an image or large text block).
Target: Less than 2.5 seconds - First Input Delay (FID) (being replaced by INP)
Measures how quickly your site responds when someone interacts for the first time—like clicking a button or typing in a form.
Target: Less than 100 milliseconds - Cumulative Layout Shift (CLS)
Measures how much content on your page “jumps around” as it loads. You’ve probably seen this happen when you’re about to click a button and it suddenly moves.
Target: Score below 0.1
Note: FID is being phased out in favor of INP (Interaction to Next Paint), which gives a more complete picture of responsiveness across the whole page lifecycle.
Why business owners should care
These metrics aren’t just technical jargon—they directly impact how people perceive your site:
- A slow-loading homepage? Visitors bounce.
- A button that doesn’t respond fast enough? Missed lead.
- Text that moves around mid-scroll? Frustration builds.
And if Google sees your site as frustrating to use, your rankings can suffer—especially on mobile.
How to test your Core Web Vitals
You don’t need to be a developer to check how your site performs. Try:
- PageSpeed Insights (by Google) – Gives you scores and actionable advice
- Google Search Console – Offers Core Web Vitals reports for your entire site
- Lighthouse or Chrome DevTools – For deeper technical audits
These tools don’t just tell you what’s wrong—they usually suggest how to fix it.
What affects Core Web Vitals?
A few common culprits:
- Unoptimized images – Too large or not lazy-loaded
- Render-blocking scripts – JavaScript and third-party tools delaying content
- Slow hosting – Cheap servers or overloaded environments
- No caching – Every visitor gets a fresh load, every time
- Font loading delays – Web fonts that block rendering
A developer or performance-focused agency can help you prioritize fixes, but even switching to better hosting or compressing images can make a noticeable difference.
Bottom line
Core Web Vitals are about making your site faster, smoother, and more pleasant to use. They’re good for SEO, good for conversions, and good for your visitors. If your website is a key part of your business, improving these metrics isn’t just a technical upgrade—it’s a smart investment in better results.
