What is the first input delay

What is the first input delay?


The First Input Delay (FID) measures the time that elapses between a user entering a website and the response from that website. Since a better value is a positive user experience, websites with a lower FID, which is part of the Core Web Vitals, are rewarded in the search results.

What is a good FID score?

The FID value is divided into three segments. The following criteria, which Google has identified itself, currently apply:

– Good: All websites that return a response within a maximum of 100 milliseconds receive a good result from Google. Fast servers and a stable internet connection are a prerequisite for this.

– Needs improvement: If the website needs a period of 100 to 300 milliseconds for its response, Google already rates this with a poorer FID value.

– Bad: All entries that take more than 300 milliseconds to answer are severely penalized by Google. Websites that fall into this category should urgently work on improving the status.

The First Input Delay is currently divided into three levels. Google reserves the right to change these values ​​in the future through technological changes or perhaps a different user behavior. Together with the Cumulative Layout Shift (CLS) and the Largest Contentful Paint (LCP), these three criteria result in the Core Web Vitals.

What is recognized as first input?

With FID, Google only measures input results that come from various discrete actions. This includes tapping buttons or pressing a key or a mouse click. Other actions, such as scrolling on a website, are not added. These points and, for example, animations are determined with a different value.

How is the FID measured?

There is no benchmark for the first input delay. It is only ever measured under real conditions when people interact with websites and thus have a “real” user experience. Certain conditions are more often responsible for a poor FID value.

Large delays arise, for example, between the time of the FCP (First Contentful Paint, i.e. the first contact and download of website elements) and the TTI (Time To Interactive, i.e. the time that passes until CSS stylistic devices and other elements are loaded). Most of the time, the website has already rendered part of the content and displays it in the browser, but the user cannot yet interact with these elements or can only interact with them unreliably. This scenario would increase the first input delay and the score would therefore decrease.

The FID value can currently only be viewed in the Google Search Console. The data that is recorded there comes from the Chrome User Experience Report (CRUX).

Meaning of the first input delay

There are several reasons why a high FID is undesirable:

  1. A good first impression is important, which is why the First Input Delay is also part of the Google Page Experience. If delays occur when entering the website, this does not inspire confidence in the visitor. The user experience suffers, which is why the site is penalized accordingly for this indulgence.
  2. There is a difference between the delays that occur after a web page is loaded and the delays that occur on the first entry (FID). By dividing this value, Google can probably give better recommendations to website owners. For example, loading less JavaScript in the browserin advance is effective against a high first input delay, but not against later delays. The division thus creates clarity.
  3. Google believes that the biggest problems with the interactivity of websites today occur when the website is loading – i.e. in the area where the FID is relevant. Once this process is complete, most websites will be quick enough. By bringing the first input delay to the fore, Google is trying to increase awareness of the problem in this area and thus improve the interactivity of many websites.

Furthermore, measuring the FID could lead to leaner, more efficient websites being developed. These would load less data in advance in the critical phase – which plays a major role in the mobile sector – and can therefore be operated more elegantly.

Improve first input delay

According to growtheology, there are several methods of improving the first input delay and thus increasing usability – both on the hardware side and on the software side. If you are interested in the topic, another guide is available that is explicitly dedicated to this matter.

What is the first input delay