Synonyms: Response delay
FID stands for First Input Delay, a metric used in web performance to measure how quickly a webpage responds to a user’s first interaction. This could be anything from clicking a button to tapping a link or pressing a key. FID is part of Google’s Core Web Vitals, a set of important factors that affect the overall user experience on a website.
The primary goal of FID is to assess the responsiveness of a webpage. A low FID score indicates that a site responds quickly, creating a smooth and seamless user experience. Conversely, a high FID score suggests that users are likely to experience a frustrating delay after their first interaction.
FID is typically affected by factors like heavy JavaScript execution, which can cause delays in a browser’s ability to respond to input. It’s especially relevant for interactive sites like e-commerce platforms, where users expect immediate feedback.
Google recommends an FID of less than 100 milliseconds to ensure an optimal experience. Improving FID usually involves optimizing your website’s code, reducing JavaScript execution, and enabling efficient browser rendering.