Core Web Vitals Simulator

Page Resource Inputs

Optimization Tips

    Set Your Speed Budget

    Your Budget Breakdown

    1,250 KB
    Total Page Weight Budget

    Recommended Limits

    Resource Type Budget Typical Range

    Core Web Vitals Thresholds

    Metric Good Needs Improvement Poor
    LCP (Largest Contentful Paint) ≤ 2.5s 2.5s - 4.0s > 4.0s
    INP (Interaction to Next Paint) ≤ 200ms 200ms - 500ms > 500ms
    CLS (Cumulative Layout Shift) ≤ 0.1 0.1 - 0.25 > 0.25

    What Do They Mean?

    LCP - Largest Contentful Paint

    Measures loading performance. The time it takes for the largest content element (image, video, or text block) to become visible in the viewport.

    INP - Interaction to Next Paint

    Measures responsiveness. The latency of all user interactions throughout the page lifecycle, reporting the worst interaction (excluding outliers).

    CLS - Cumulative Layout Shift

    Measures visual stability. The sum of all unexpected layout shifts that occur during the entire lifespan of the page.