Core Web Vitals Checker.
The Core Web Vitals checker measures the 3 key metrics that, according to Google, are essential to delivering a great user experience on the web. To perform the Core Web Vitals test this tool is powered by real-world Chrome user data.
What are the Core Web Vitals?
The Core Web Vitals are a set of metrics (Largest Contentful Paint, First Input Delay & Cumulative Layout Shift) designed to measure user experience. The Web Vitals are part of the Google Page experience signals together with existing Search signals for page experience, including mobile-friendliness, safe-browsing, HTTPS-security, and intrusive interstitial guidelines. Core Web Vitals are important metrics, because Google will start using them as ranking signals starting in 2021.
Core Web Vitals test report
- Load time – Largest Contentful Paint (LCP), measures the render time of the largest image or text block visible within the viewport.
- Interactivity – First Input Delay (FID), the time between a user action and browser response.
- Visual stability – Cumulative Layout Shift (CLS), the sum of individual layout shift scores, during page load.
Core Web Vitals score evaluation
|Contentful Paint (LCP)||<2500 ms||<=4000 s||>4000 ms|
|First Input Delay (FID)||<100 ms||<=300 ms||>300 ms|
|Cumulative Layout Shift (CLS)||<0.1||<=0.25||>0.25|
How to pass the Core Web Vitals test?
Core Web Vitals Score
- Pass – Your page scores meets the recommended targets at the 75th percentile for all of the above three metrics.
- Fail – Your page scores doesn’t meet the recommended targets.
How to optimize for Core Web Vitals?
#1 Optimize Largest Contentful Paint time
When it comes to technical website optimization there is no “one-size-fits-all” solution, but when we look at the most common causes for a slow Largest Contentful Paint.
- Slow server response times.
- Slow resource load times.
- Client-side rendering.
#2 Optimizing First Input Delay
- Split code that blocks the main thread for more than 50 ms.
#3 Optimize Cumulative Layout Shift
In many cases a high CLS score is related to:
- Images that don’t have their dimensions specified.
- Ads, embeds, and iframes without dimensions
- Dynamically injected content
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