SEO Glossary > First Input Delay (FID)

First Input Delay (FID)

The First Input Delay (FID) is a Core Web Vitals metric that measures the time when the user starts interacting with a page to the time when the browser begins processing even handlers in response to that interaction. The interaction includes: click on a link, click on a button, or other custom control.

The breakdown as follows:

Good: 0-100 ms
Needs Improvement: 100-300 ms
Poor: 300 ms and longer


Core Web Vitals