Chrome Confirms INP Replaces FID in Core Web Vitals — Action Required

What Changed

Google finalised INP — Interaction to Next Paint — as the third Core Web Vital, replacing First Input Delay (FID). INP scores above 200ms trigger a negative Page Experience ranking adjustment.

INP Thresholds

• Good: ≤ 200ms
• Needs Improvement: 200–500ms
• Poor: > 500ms

Why INP Is Harder Than FID

FID measured only the first interaction. INP measures every interaction and reports the worst-performing one. A page with a heavy click handler (e.g. a React state update) will score poorly even with a great LCP.

Quick Wins for Better INP

• Defer non-critical JavaScript (ads, analytics) after the first user interaction
• Use startTransition() in React for non-urgent state updates
• Use next/dynamic with ssr: false to defer heavy components

Practical Takeaway

Run a PageSpeed Insights audit on your five most-visited pages. Filter by INP. If above 200ms, the quick win is usually a large JavaScript bundle loading before interaction.