Blurred background image

First Input Delay in Simple Terms

First Input Delay in Simple Terms

First Input Delay (FID) is a user experience metric that makes up one part of the Core Web Metrics.

But how to make sense of this metric? Let’s take a look at FID and consider what it does and its role in Google’s Core Web Metrics.

Rather than just a random metric that is randomly selected by Google, First Input Delay has real-world benefits to brands and retailers that affects traffic, leads, sales, and revenue.

The definition of First Input Delay

First Input Delay in Simple TermsFirst Input Delay is the measurement of time that it takes for a web browser to respond to the first interaction of a visitor of a website while it’s loading.

Such interaction covers a range of things such as clicking on a button, on a link, and a keypress. And it includes those text input areas, the dropdowns, and the checkboxes. 

However, scrolling and zooming are actions that don’t count as interactions given that there is no response that is expected from the actual site itself.

The essence of First Input Delay is to measure the responsiveness of a website while it’s loading.

First Input Delay typically occurs when text or images download on a page in a non-orderly way, which causes the page to pause excessively. Then start. And pause again before restarting. This in turn causes unresponsive behavior for a website visitor when they try to interact with the page.

First Input Delay in Simple TermsI like to think about First Input Delay as a simile for a traffic jam that is caused when the lights malfunction and flicker and chaos ensues.

According to Google, they describe input latency in the following way: “In general, input delay (a.k.a. input latency) happens because the browser’s main thread is busy doing something else, so it can’t yet respond to the user.

“One common reason this might happen is the browser is busy parsing and executing a large JavaScript file loaded by your app. While it’s doing that, it can’t run any event listeners because the JavaScript it’s loading might tell it to do something else.”

Fixin’ it

The curse of poor scores related to First Input Delay is the unorganized downloading of images and text. And so the way to fix the problem is to thoroughly organize how these images and texts are presented to the browser.

And this means using HTML to control how scripts are downloaded. It means the optimization of images. And it means comprehensively omitting those texts and scripts that were simply unnecessary. The point is to optimize what is actually downloaded to get rid of the rolling pauses and starts of downloads on a webpage.

PS: ArganoUV is one of the world’s leading Core Web Vitals consultancies. Contact us to see how we can work together.

Related Ideas

If you got value from this article, you may enjoy these other articles, as well. We’re always adding value!

What is the Weight of Core Web Vitals?
  • ArganoUV
  • Core Web Vitals

What is the Weight of Core Web Vitals?

The importance of Core Web Vitals are weighted. But which weighs heavier than the others? ...
What is This 'Core Web Vitals' Thing Everyone is Talking About?
  • ArganoUV
  • Core Web Vitals

What is This 'Core Web Vitals' Thing Everyone is Talking About?

Affecting every single Google page performance is the new Core Web Vitals. But what are they...
Core Web Vitals for Mobile
  • ArganoUV
  • Core Web Vitals
  • Technology

Core Web Vitals for Mobile

Why is mobile the most important aspect for Core Web Vitals?

Latest ideas

Our latest thinking about SF Commerce Cloud.

The Page Experience Report
  • ArganoUV
  • Core Web Vitals

The Page Experience Report

What is to be found in Google’s page experience report?
The Supply Chain Issue and Nearshoring
  • ArganoUV
  • Commerce

The Supply Chain Issue and Nearshoring

How can nearshoring help solve the supply chain issue?
The Impact of Page Experience Metrics
  • ArganoUV
  • Core Web Vitals

The Impact of Page Experience Metrics

What is the impact of Google’s page experience metrics?

How can we achieve
awesomeness together?