Demystifying INP: New tools and actionable insights

This article by Vercel's CTO is a technical guide on how to improve Interaction to Next Paint (INP) scores on websites using real-world strategies. INP became part of Google's Core Web Vitals in March 2024 and is important in understanding user experience on websites. However, it is often misunderstood. INP is about giving the user feedback that their input is being processed within 200ms and not necessarily about painting the full user response within this time. The article provides examples of how to achieve a good INP score and introduces the new module await-interaction-response, which helps separate acknowledging user interaction from the expensive operation. Along with this, the author also introduces new features from Vercel to help reproduce INP issues and optimize performance.