Loading speed LCP:
Largest Contentful Paint | LCP
Loading speed is measured by Largest Contentful Paint (LCP), the metric reporting the render time of the largest image or text block visible within the first viewport.
User experiences are categorized as follows:
- Good: Less than 2.5 seconds,
- Needs Improvement: Between 2.5 and 4 seconds,
- Poor: Above 4 seconds.
Interactivity FID:
First Input Delay | FID
Interactivity is measured by First Input Delay (FID), the metric reporting the time from when a user interacts with a page, such as tapping a button, to when the browser is able to process that event.
User experiences are categorized as follows:
- Good: Less than 100 milliseconds,
- Needs Improvement: Between 100 and 300 milliseconds,
- Poor: Above 300 milliseconds.
Visual stability CLS:
Cumulative Layout Shift | CLS
Visual stability is measured by Cumulative Layout Shift (CLS), the metric reporting the layout shift scores during the lifespan of a page. Each time a visible element changes its position unexpectedly, the page's layout shift score worsens.
User experiences are categorized as follows:
- Good: Less than 0.1,
- Needs Improvement: Between 0.1 and 0.25,
- Poor: Above 0.25.