First Input Delay is one of the Essential Web Vital metrics which calculates the amount of time it takes for a browser to answer to a user’s first interaction with a page. This interaction could be either in the form of click in a link, tap on a button, or interaction with other elements on the page.

Some other forms of interaction could be a click on checkboxes, drop-downs or download of a guide.

Therefore First Input Delay calculates interactivity. Its calculates the time a website takes to answer after the visitor interacts. Google uses FID as an essential ranking factor. The goal of FID is to calculate and measure the responsiveness of a website when it is loading.

FID calculations of  the first interaction: 

FID only measures and do calculations of the first impressions and the first time when a user interacts with  the web page.

FID assists webmasters address delayed first answer and makes sure that loading critical resources do not  make their site irresponsive or hang.

What is the cause of First Input Delay?

Usually, FID is usually caused by images, videos, or scripts which load in a non-orderly manner. An unsettled loading causes the web page to load, pause, re-load, and then pause resulting in ignore behaviour towards users first interactions.

What is a good FID score?

Core Web Vitals scores can put into three categories: Good, Needs to be Improved and Poor.

* Good: LCD needs to be less than 100 milliseconds to provide a good user experience.

* Needs Improvement: LCD requires improvement between 100 to 300 milliseconds

* Poor: LCD is beyond 300 millisecond and it is a poor score and needs to be improved very much.

How to measure the First Input Delay?

However, the First Input Delay is a field metric so it can be measured by these tools:

* Page insight (Field Data)

* Search console– Core Web Vitals report.

* chrome experience user reports (CrX)

Webmasters can calculate the total blocking time and proxy metrics on these:

  1. Lighthouse
  2. Pagespeed insights
  3. Chrome devtools
  4. Webpage test


The publishers should take the above mentioned steps to improve the first input delay score. And for more information don’t forget to sign up on