What is First Input Delay (FID)?

First Input Delay (FID) is a user-centric metric that measures the time it takes for a web page to respond to a user's first interaction. This includes clicks, taps, or keyboard input from the user.

FID is an important metric because it helps measure how responsive and interactive a website or web application is. A long FID can lead to frustration for users, causing them to abandon the site and seek alternatives.

In order to optimize FID, developers need to ensure that their website's JavaScript code is efficient and does not cause any unnecessary delays in response times.

The Impact of FID on User Experience

First Input Delay (FID) has a significant impact on user experience as it determines how quickly users can interact with your website. Slow FIDs result in slow response times when interacting with elements on a web page which makes using the site frustrating and sometimes impossible. This often leads users to leave your site in search of faster alternatives.

Optimizing for fast FIDs ensures your users have an enjoyable experience while using your website. As such, optimising for fast FIDs becomes more critical if you want to retain customers over time.

Faster Load Times Equals Faster First Input Delays

The speed at which content loads onto your pages plays an essential role in determining how quickly users can interact with those pages - this includes both Fully loaded Speed Index, Largest Contentful Paint, among others. The longer these take, the slower the First Input Delay (FID).

To improve these load times, work on optimizing images and other assets; compressing files before uploading them to the server, minimizing the number of requests needed to load a page and using a Content Delivery Network (CDN) to serve files from multiple locations.

FID and SEO

First Input Delay (FID) is now an essential metric that Google uses in their recent Core Web Vitals update. This update aims to measure and rank user experience on websites. A website with fast FID will have higher rankings than one with slow FIDs. As such, optimizing for fast FIDs has become increasingly critical if you want to rank highly on search engines results pages (SERPs).

To improve your website's ranking position, ensure your site has fast FIDs by making sure it's optimized for speed as well as ensuring it's mobile-friendly.