Interaction to Next Paint (INP) will replace First Input Delay (FID) as a Core Web Vitals metric starting in March 2024, Google announced at Google I/O today.

Google hinted at this change for about a year now. But now it’s official.

What is Interaction to Next Paint? INP is a metric that uses data from the Event Timing API. It assesses the responsiveness of a webpage.

An interaction that causes a page to become unresponsive results in a poor user experience, Google said. INP observes the latency of all interactions a user has made with the page and reports a single value which all (or nearly all) interactions were below.

Google provided the following example of what poor versus good responsiveness looks like:

On the left, long tasks block the accordion from opening. This causes the user to click multiple times, thinking the experience is broken. When the main thread catches up, it processes the delayed inputs, resulting in the accordion opening and closing unexpectedly.

Rankings impact. Google reiterated that Core Web Vitals do not guarantee good rankings in Google Search, wrote Martin Splitt, Developer Relations Engineer at Google.

• “Great page experience involves more than Core Web Vitals. Good stats within the Core Web Vitals report in Search Console or third-party Core Web Vitals reports don’t guarantee good rankings,” according to Splitt.

A good page experience is part of Google’s overall core ranking system. Core Web Vitals – while maybe not a direct ranking signal – is one way you can try to understand whether you’re achieving a good page experience.

However, Google uses other signals as part of its core ranking system to determine what makes a good page experience, outside of Core Web Vitals.

“There are many aspects to page experience, including some listed on this page,” Danny Sullivan, Google’s Search Liaison, told Search Engine Land. “While not all aspects may be directly used to inform ranking, they do generally align with success in search ranking and are worth attention.”

What is changing. Google will replace the FID metric with the INP metric as part of the Core Web Vitals in March 2024. Google Search Console will include INP in the Core Web Vitals report later this year so you can start measuring your new INP scores.

When INP replaces FID in March 2024, the Google Search Console report will stop showing FID metrics and use INP going forward.

Why we care. A lot of SEOs have focused a lot of time on Core Web Vitals and the FID score, for better or worse. Now those same SEOs will likely shift their focus from FID to INP. Here is a guide from Google on how to optimize for INP.

Overall, I still recommend you don’t get bogged down in these metrics. Even Google says they’re only one aspect to consider when looking to improve your site’s page experience.

You know, when browsing your website, whether it is responsive and fast. You don’t always need a third-party tool to tell you that. So make excellent sites for your users but don’t obsess about these scores.