FIP

First Input Delay

Google’s measure of user and page experience activity in its Core Web Vitals. This is being replaced by Interaction to Next Paint (INP).

It specifically measures the time from when a user first interacts with a page (i.e., when they click a link, tap a button, or use JavaScript-driven controls) to the time when the browser is able to respond to that interaction.

In simple terms, FID is the delay between the user’s input and the browser’s response. A low FID implies a more responsive and user-friendly interface, which is what users generally prefer. According to Google, a good FID score is less than 100 milliseconds, while anything above 300 milliseconds needs improvement.

FID is particularly important for sites where users need to do something, because this is where interactivity really matters. For instance, it’s crucial for pages where users have to input data, click on items, or navigate through the website.

It’s worth noting that FID is different from other metrics like First Contentful Paint (FCP) and Largest Contentful Paint (LCP), which measure how quickly a page starts loading and how quickly the main content of a page loads, respectively. FID, on the other hand, focuses on the interactivity and responsiveness of a page.

• Abbreviation: FIP
• Source: Core Web Vitals