Core Web Vitals Calculator
Use our free Core Web Vitals calculator to evaluate LCP, INP, and CLS scores instantly. Identify performance issues and boost your SEO rankings today.
About Core Web Vitals Calculator
The Core Web Vitals Calculator evaluates key Google page experience metrics, including Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS). Input your performance metrics to determine whether your web pages meet Google's official speed and usability thresholds.
Designed for technical SEOs, web developers, and site owners, this tool runs entirely in your browser with no software installation or account registration required. Test, benchmark, and plan your site performance improvements quickly and accurately.
Key features
- Evaluates LCP, INP, and CLS metric thresholds
- Instant performance scoring directly in your browser
- Clear Good, Needs Improvement, and Poor ratings
- Simulates impact of metric changes on scores
- Completely free with no account registration needed
- Client-side processing ensures complete data privacy
How to use Core Web Vitals Calculator
- Input your recorded LCP, INP, and CLS metric values.
- View the automated calculation for each performance indicator.
- Check your overall status against Google passing criteria.
- Adjust individual values to simulate optimization gains.
Who is it for?
- SEO professionals preparing technical site audits for clients
- Front-end developers debugging page speed and layout stability
- E-commerce store owners working to reduce checkout bounce rates
- Content publishers optimizing ad placements to avoid layout shifts
Frequently asked questions
What are Core Web Vitals?
Core Web Vitals are a standardized set of user-experience metrics defined by Google. They measure real-world performance focusing on loading speed (LCP), responsiveness (INP), and visual stability (CLS).
What are the target thresholds for passing Core Web Vitals?
To achieve a Good rating, your page should have an LCP of 2.5 seconds or less, an INP of 200 milliseconds or less, and a CLS score of 0.1 or lower at the 75th percentile of page loads.
Did INP replace FID in Core Web Vitals?
Yes, Interaction to Next Paint (INP) officially replaced First Input Delay (FID) as a Core Web Vital in March 2024 to provide a more comprehensive measure of overall page responsiveness.
Is this Core Web Vitals calculator free?
Yes, this browser-based calculator is completely free to use with no account creation or subscription required.
How do Core Web Vitals impact SEO rankings?
Core Web Vitals are part of Google's page experience ranking signal. Passing these metrics helps improve search rankings, especially when competing against pages with similar content quality.