First Input Delay (FID)
Measures the time from when a user interacts with the page to when the browser can process that interaction.
The scores we use come from a Google Lighthouse report and represent the 28 day average score for the homepage as measured by real users using Chrome. Websites should aim for FID of less than 100ms. Anything over 300ms is considered to be poor.
For more information, please read the documentation on Web.dev.