INP is Interaction to Next Paint, a responsiveness metric that replaced FID as a Core Web Vital.
It matters because technical issues can prevent great content from being discovered, rendered, indexed, or trusted. Strong technical foundations protect rankings during redesigns, migrations, content expansion, and platform changes.
Example
Example: If tapping a mobile menu or form field feels delayed because JavaScript is blocking the main thread, INP may be poor. Reducing script work and improving event handling can make the page feel faster.