Handy guide to First Input Delay (FID) | What & Why?

Before talking through the First Input Delay, why not get a little bit of background knowledge first.

Websites cope up with all the users’ queries on the search engines with the relevant information fastly. Google especially is a reliable source to provide the most appropriate information, keeping the user experience the topmost priority.

Yes, you have read it right; we said “user experience.” To ensure it, Google has been changing its ranking algorithms. For example, Google has added the core web vitals into page experience signals as a ranking factor. Page experience simply is how users perceive the webpage. Read Page Experience Update for detailed information. Thus, one of those core vitals metrics is First Input Delay (we will discuss today!). 

It means the websites having a good page experience will be ranked by Google. To get such a website that Google loves to rank, you need to work with a professional SEO company and expert Website Development Company.

Wondering! why we said so? SEO sure is related to ranking; however, what is development doing here?

You will get an answer to this question in a few seconds in this post.

What is First Input Delay?

Abbreviated as ‘FID,’ it is a real-user-centric performance metric. It computes the time taken to respond to the first user interaction with a page.

That is, when a user clicks or taps any button or link on the page, it will be the first impression or interaction. Similarly, the browser is going to take action and respond to the request, and it will be the processing of the interaction.

So is the name ‘First Input Delay’; that is, FID will measure the delay in between the first interaction (input by the user) and the response of the page to that interaction. Remember, it tracks the delay time only, not the processing time. This measurement comes out in milliseconds. 

• A good FID score is the time less than 100 ms. (the page will load and respond quite faster)
• While if the delay time is above 300 ms, it is a poor score. (and will render a lousy user experience)
• The time between 100 to 300 ms is somehow average. (It will be more like taking a little time to load but not irritate the users)

Why the First Input Delay occurs?

Here comes the development part relating to the Website Development Company. 

Briefly, the leading cause behind the delay seems to be the browser, preoccupied with other tasks. That is leading to no response when a user taps a button, a link, or presses a key. If the browser isn’t responding, the website has to wait to load the user request.

Now the question is, what is the browser doing, anyway?

• Weighty JavaScript Files 

One of the compelling reasons is that there is quite a weighty JavaScript lying behind. Thus, loading all the JavaScript code and scripting takes time, causing slower page response times. Meanwhile, the loading, the user has to wait too, indicating the delay after the first input. 

• The monopoly of the long-running task in JavaScript

The second reason can be the long-running task in JavaScript. It’s because such tasks take over the main thread (that is responsible for rendering JavaScript). Eventually, the User Interface (UI) gets to freeze, and the page becomes unresponsive to user input even if it looks ready. Hence, end up giving a bad user experience to the users.

• Presence of the Unused JavaScript

Briefly, JavaScript files being render-blocking block the browser from dealing with other page load tasks. Therefore, unused or using additional JavaScript will take more time to load, causing the First input delay issue.

As we mention, the above can be the common grounds for delaying the interaction and response times. It indicates that the coding needs to be optimized. That is why we said to let a Website Development Company that has a long run experience of websites and development work on your website. 

If your website’s web pages have a First Input Delay issue, you need to sort this problem out. Contact the development company to overhaul the underlying issues instantly because websites are all about first impressions. However, a bad experience annoys the visitors to lose interest no matter the website aesthetics and engaging content. Eventually, your website analytics, like bouncing rate, will increase, and staying time and traffic will lessen in no time. On top of that, SEO rankings will be in danger too.

Therefore, you should not be ruining the first interaction and impression if you want the visitors to convert as your customers. Besides, securing high SEO rankings per Google’s page experience update. In the next post, we will share the simple ways to optimize the First Input Delay. It will help you get rid of input delay issues, so stay tuned to get helpful information.