Jeremy Wagner is more of a writer than a web developer, but he does both anyway. On top of making websites for longer than he thought probable, he has written for A List Apart, CSS-Tricks, and other publications. Jeremy will someday relocate to the remote wilderness where sand has not yet been taught to think. Until then, he continues to reside in Minnesota's Twin Cities, bemoaning the existence of strip malls.

Understanding and Optimizing INP (Interaction to Next Paint)

Did you know that 90% of time spent on most web pages is after page load? In this span of time, users are interacting with your website through a series of interactions such as clicks, taps, and keyboard inputs—and the slower your website is to respond to those interactions, the more likely your users will have a negative user experience with your website.

Significant time has been invested in creating new metrics to assess page responsiveness. One of these metrics is First Input Delay (FID), which is a load responsiveness metric that captures the input delay of the first interaction. However, a new responsiveness metric that samples more than just the first interaction was needed to truly measure interaction latency—and more than simply an interaction's input delay.

In order to comprehensively assess overall page responsiveness, the new Interaction to Next Paint (INP) metric was created. INP samples all page interactions, and goes beyond measuring just the input delay. In this talk, you'll find out all about INP, how it works, why it matters, how you can measure it, and how you can improve it.