Is your website ready for Google’s new Interaction to Next Paint (INP) metric? Replacing First Input Delay in March 2024, this innovative metric prioritises the entire user experience, not just the first click. Here’s everything you need to know about INP and how to prepare your site for this change.

Google has announced a significant update to its Core Web Vitals (CWV), which are key factors for the measurement of user experience on websites. The new metric, known as Interaction to Next Paint (INP), is set to replace the current First Input Delay (FID) in March 2024.

What is Interaction to Next Paint (INP)?

INP measures the responses of all user interactions on a page and provides a single cumulative value representing the longest time observed during these interactions. This new metric will offer a broader understanding of the user experience by evaluating all user interactions instead of focusing on just the initial one.

This shift from FID to INP reflects data from Chrome, indicating that 90% of a user's time on a page occurs after the initial load. Thus, assessing the entire user interaction landscape rather than just the first input will provide a more comprehensive view of a page's performance.

What does INP Measure?

INP takes into account three main forms of user interaction: mouse clicks, device taps, and keyboard presses. By capturing these interactions, INP gauges how well a page responds to these inputs and consequently provides visual feedback.

For instance, consider an eCommerce site. When a user adds an item to their shopping cart, they typically receive visual confirmation that the button has been pressed and the cart has been updated. If there is a delay in providing this feedback, it can create an impression of poor responsiveness, negatively impacting user experience.

Google's new metric is meant to capture these kinds of delays. To aid in the understanding of this concept, Google has released a video showcasing the difference between good and poor INP values using expandable Frequently Asked Questions (FAQs) as examples. In a good INP scenario, the expandable content loads immediately. In contrast, poor INP is characterised by a 1-2 second delay between the user click and the content response.

INP Scoring Criteria

The responsiveness of a page is categorised into three groups based on INP values:

  • Below 200 milliseconds: Good Responsiveness
  • Below 500 milliseconds: Needs Improvement
  • Above 500 milliseconds: Poor Responsiveness

Google asserts that a lower INP value indicates a higher level of responsiveness to user inputs, thus delivering a better user experience.

Measuring INP

Website owners and developers will be able to measure their pages' INP values using tools such as Google's PageSpeed Insights, Lighthouse, and the Chrome User Experience Report. These resources will provide data to help optimise a website's performance and enhance user interactions.

In conclusion, the introduction of INP as a Core Web Vitals metric underscores Google's commitment to prioritise the user experience in web browsing. The shift from FID to INP offers a more holistic view of a page's responsiveness, allowing developers to identify and address potential areas of improvement more effectively. As we head towards March 2024, businesses need to adjust to this change to ensure their websites continue to offer a positive user experience and maintain their online visibility in the face of Google's ever-evolving algorithms.