Google has announced that its new Interaction to Next Paint (INP) metric will officially replace First Input Delay (FID) as a Core Web Vital on March 12.
INP measures when a user interacts with a page (e.g., clicking a button) to when the browser can render the changed pixels to the screen. It aims to capture aspects of interactivity that FID didn’t.
Evolving Web Metrics
FID, which measured the time to first paint after a user’s first interaction, was introduced in 2018 as part of Google’s Web Vitals initiative. Web Vitals provides metrics to help web developers optimize critical aspects of the user experience.
Over time, Google realized FID’s limitations in assessing interactivity, leading to INP’s introduction as an experimental metric in May 2022. After a transition period as a ‘pending metric,’ Google has confirmed that INP will officially replace FID in March.
Preparing For Change
As the INP transition approaches, developers should verify if their website’s INP meets the “good” threshold, which reflects performance at the 75th percentile of page loads.
For sites not currently meeting the “good” INP threshold, Google recommends taking these steps to optimize for the transition:
Evaluate current INP performance using tools like PageSpeed Insights and Chrome’s User Experience Report.
Diagnose issues slowing down INP, like long JavaScript tasks, too much main thread activity, or a large DOM.
Optimize problematic areas following Google’s optimization guides. This may involve streamlining JavaScript, reducing input delay, simplifying the DOM structure, or refining CSS selectors.
Broader Implications For Web Development
Google’s implementation of INP as a Core Web Vital could impact web development and user experience in several ways:
- INP scores may influence websites’ search engine rankings and user engagement, as Google uses Core Web Vitals in its ranking algorithm.
- Web development practices may evolve to focus more on optimizing interaction readiness, which could require application architecture and code changes.
- Performance monitoring tools and strategies may need to be updated to track and analyze the new INP metric.
In Summary
As Google transitions to the INP metric in March, web developers should evaluate their site’s performance and take steps to optimize areas impacting interactivity.
With interactivity becoming a more significant factor in search rankings and user engagement, developers should prepare now to ensure a smooth changeover.
Featured Image: salarko/Shutterstock
