First Input Delay (FID)
FID measured how long the browser waited before it could start handling the very first tap or click on a page. It was a Core Web Vital from 2020 until 12 March 2024.
What FID measured, and what it missed
FID captured only the input delay: the gap between the user’s first interaction and the moment the main thread was free to run the event handler. It ignored how long the handler itself took, how long the next frame took to paint, and every interaction after the first.
That made it easy to pass. According to Chrome UX Report data published by Google, over 90% of origins had good FID on mobile, while many of those same sites felt sluggish when you actually used them. The metric wasn’t telling developers anything.
Why INP replaced it
Interaction to Next Paint measures the full latency of nearly every interaction during a visit, from input to the next paint, and reports one of the worst. Google announced it as a pending Core Web Vital in May 2023 and swapped it in on 12 March 2024. Search Console, PageSpeed Insights and the CrUX API stopped reporting FID afterwards.
If a report still mentions FID
Older SEO audits, plugins and documentation may still show FID. Treat it as outdated: a good FID tells you nothing about whether you pass today’s assessment. Check your INP in the checker instead. The fixes overlap: long main-thread tasks during load hurt both, so the Total Blocking Time advice still applies.
Check it on your own page
Field and lab numbers for mobile and desktop, in about 30 seconds.
Questions people ask
Is First Input Delay still used?
No. Google replaced FID with Interaction to Next Paint as a Core Web Vital on 12 March 2024, and its tools no longer report FID.
What was a good FID?
100 milliseconds or less at the 75th percentile; over 300 ms was poor.
Can I still check FID for my site?
Not through Google’s current tools. Check INP instead, which is the metric Google uses today.