Search and SEO
What is Interaction to Next Paint?
Interaction to Next Paint measures how long a page takes to visually respond to a user interaction, assessed across the whole visit rather than the first click alone. It replaced First Input Delay in 2024 and the target is under 200 milliseconds.
Also called: INP
Why it is harder to fix than LCP
LCP and CLS respond well to sequencing changes — preload this, reserve space for that. INP does not, because it measures how busy the main thread is when someone interacts. The only durable fix is doing less work.
What actually reduces it
- Ship less JavaScript. Architectural, and by far the most effective lever
- Break long tasks so the browser can respond between them
- Avoid layout reads inside high-frequency handlers such as mousemove and scroll
- Audit third-party tags. Most sites carry several nobody has justified since installation
- Remove animation that runs permanently in a requestAnimationFrame loop
The architectural answer
If a page does not need a framework at runtime, do not ship one. A statically generated page with no framework JavaScript has an interaction cost at the browser floor, which no amount of optimisation on a heavy page will match.
Where this is covered in depth
A definition can only go so far. Core Web Vitals, and the order that actually reduces them covers this properly — 3 minutes, free, no email required.
Who wrote this
Anas Bin Masud builds e-commerce sites and does technical SEO for businesses in the UK, Canada and Pakistan. These definitions come from client work rather than from a content brief — where an entry describes a mistake, it is usually one found on a real site. More about how I work.