Extended definition
Time between user click and visual response. Replaces FID since March 2024. Target: under 200 ms.
Context and application
INP is stricter than the old FID because it measures ALL interactions, not just the first. Sites that seemed OK on FID (under 100ms) can fail on INP if they have heavy handlers on scroll, hover, click on interactive components. Most common sources of bad INP: React rendering cascade on state changes, third-party scripts (Intercom, HubSpot, ad networks) that block main thread, animation libraries that recalculate layout. Web Workers and debouncing are tactical solutions. Eliminating useless third-parties is the strategic solution.
In practice
optimize heavy JavaScript and event handlers.
How SEO Master PRO MAX helps
For INP (Interaction to Next Paint), the relevant module in the app is Speed module. See the dedicated page for how it works concretely on your site.
See Speed module →