Interaction to next paint (INP) will replace first input delay (FID) as score web vitals metric starting this March 2024. which was announced earlier in 2023 at Google I/O.

What is the Interaction to Next Paint? 

Interaction to Next Paint (INP) is an upcoming core web vitals metric that measures web page response according to user interaction with a web page, for example, by clicking a button.

When a user takes an action browser sends a request to the web server for new content and the web browser sends the new content to the browser and the browser renders the new content on the page, the way browser measures the time it takes to render the new content and content and reports it as the INP score.

Comparison between  INP and FID

Let’s delve into the difference between interaction next paint (INO) and first input delay (FID), both of which are essential metrics in the realm of core web vitals:

FID

•   FID measures the time it takes for a website to respond to the first interaction initiated by a user.
•   It specifically considers the delay associated with the initial user action user action.
•   FID is crucial because it directly impacts user experience. A lower FID indicates a more responsive website.
•   FID only accounts for the first interaction and doesn’t consider subsequent interactions or even the handler’s processing time.     

INP

•  INP is a new metric that evaluates the responsiveness of a page’s collective interactions.
•  Unlike FID, INP considers all user interactions on the page.
•  It gauges the time taken for the website to respond to all interactions.
•  An INP score between 0 and 200 milliseconds indicates high responsiveness and interactivity.
•  INP directly affects a website’s ranking on search engines.

How is INP measured?

INP is the time difference between the user input, like clicking the button, and the UI update.

Any less than 200 milliseconds is considered good INP and more than 500 milliseconds is considered as poor and needs improvements.

A low INP value indicates that the page is highly responsive to user interaction. As part of core web vitals, INP is important for several reasons: 

1 Improved user experience: A high INP value means users have to wait a long time for the web page to react to their interactions, which can be frustrating.

2 Search engine optimization (SEO): INP and other core web vitals are part of Google’s page experience signals, determining a website’s rank on its results pages. This makes the INP SEO metric especially important.

3 lower bounce rate: slow loading time can make users abandon the page, hurting your business’s bottom line.

Optimizing Interaction to Next Paint (NIP)

1 Reducing input delay: 

Reducing the input delay component of INP breaks the background activity on the main thread.

By referring to the lab data you can see which background activity is blocking the user interaction.

Check if any third-party code is responsible for total blocking time and configure it to reduce the blocking time or if possible, load the third-party code only when it’s required.

2 Minimizing processing time:

Optimize the code and reduce the unnecessary computations. Processing time is crucial for improving website performance and providing a better user experience. These are some ways to reduce page loading time.

1 Optimize caches

2 Trime down javaScript parsing

3 Reducing HTTP requests

4 Enable compression 

5 Optimize image

6 Minimizing redirects

7 Prioritize Above-the-fold content

3 Decrease presentation delay:

Present delay depends on the complexity of your page and how frequently the page is updated.

If the rendering page content is slow then show the content which is most useful to the user and other content to load in the background. Utilize the techniques like content visibility for off-screen elements.

Tools to measure and optimize INP

1. Google PageSpeed Insights

This free website shows the INP metric indicating how quickly the page is responding to user interactions.

 Provides a snapshot of your page’s performance over the previous 28 days, including INP values.

2.DebugBear Free Website test 

This is also a free website where you can simply enter your URL, and run the test.

3. SiteSpeed by DebugBear Chrome Extension

You can install the site speed Chrome extension to view the core web vitals of the entered URL

4. The Web Vitals Libary

You can programmatically measure the INP with Javascript using the web vitals library. This gives the measurement of real-time users.

Wrapping up

 INP is not the key factor that is responsible for the ranking of a web page. It is a key metric to increase page speed and give a great user experience to the user ultimately driving sales.