Preparing For Interaction To Next Paint, A New Web Core Vital — Smashing Magazine

There’s a change coming to the Core Web Vitals lineup. If you’re reading this before March 2024 and fire up your favorite performance monitoring tool, you’re going to to get a Core Web Vitals report like this one pulled from PageSpeed Insights:

You’re likely used to seeing most of these metrics. But there’s a good reason for the little blue icon sitting next to the second metric in the second row, Interaction to Next Paint (INP). It’s the newest metric of the bunch and is set to formally be a ranking factor in Google search results beginning in March 2024.

And there’s a good reason that INP sits immediately below the First Input Delay (FID) in that chart. INP will officially replace FID when it becomes an official Core Web Vital metric.

The fact that INP is already available in performance reports means we have an opportunity to familiarize ourselves with it today, in advance of its release. That’s what this article is all about. Rather than pushing off INP until after it starts influencing the way we measure site performance, let’s take a few minutes to level up our understanding of what it is and why it’s designed to replace FID....