First Input Delay
A retired Core Web Vital that measured the delay between a user's first interaction and the browser starting to process it.
Definition
First Input Delay (FID) is a metric that measures the time from a user's first interaction with a page — such as a click or tap — to the moment the browser can begin processing the event handlers for that interaction. It was a measure of a page's initial responsiveness.
FID was a Core Web Vital with a 'Good' threshold of 100 milliseconds or less, measured at the 75th percentile. In March 2024 it was replaced as a Core Web Vital by Interaction to Next Paint (INP), which assesses responsiveness across the full lifetime of a page rather than only the first interaction. Google fully discontinued FID support in September 2024. References to FID remain useful for historical comparison, but current page experience assessment uses INP.
Examples
Historical reporting
A performance report from early 2024 lists a site's FID at 90 ms, indicating a 'Good' rating before the metric was retired.
Migration to INP
A team that previously tracked FID switches its dashboards to Interaction to Next Paint after FID stopped being a Core Web Vital in March 2024.
Sources
Related terms
- Interaction to Next PaintA Core Web Vitals metric measuring how long a page takes to visually respond to a user interaction, sampled across the page's lifetime.
- Core Web VitalsA set of three Google metrics that measure real-world page experience: loading speed, interactivity and visual stability.
- Total Blocking TimeA lab metric that sums how long the browser's main thread was blocked by long tasks after First Contentful Paint.
- Page ExperienceGoogle's umbrella term for signals describing how users perceive a page — Core Web Vitals, HTTPS, mobile usability, and absence of intrusive interstitials.
- Largest Contentful PaintA Core Web Vitals metric measuring how long the largest visible content element on a page takes to render after loading begins.
- Cumulative Layout ShiftA Core Web Vitals metric measuring how much visible content unexpectedly shifts position during the lifetime of a page.
Where QueryCatch uses this
Last updated: 16/05/2026