Google has recently updated its official Core Web Vitals documentation, specifically to give a clearer picture of the Interaction to Next Paint (INP) metric.
As a relatively new addition to Core Web Vitals, INP measures how quickly a webpage responds to user interactions, making it a critical part of understanding the user experience. This latest update highlights why specific scoring thresholds were chosen for INP and the effort behind setting an achievable benchmark across different devices.
More specifically, in this blog post, we will talk about:
- The latest changes by Google in the Core Web Vitals documentation,
- The ideal INP scores that webmasters should aim for,
- The role of mobile devices in INP scoring, and
- What website owners can do to improve their INP and CWV scores.
Ready?
Let’s begin.
What is Interaction to Next Paint (INP)?
Interaction to Next Paint (INP) is designed to assess the time a webpage takes to respond to user actions such as clicks, taps, and key presses.
Officially adopted as a Core Web Vitals metric in spring 2024, INP plays a critical role in evaluating website performance because it measures the overall responsiveness of the page rather than focusing on just the first interaction.
This is a notable shift from the previously used First Input Delay (FID), which only considered the delay of the initial interaction, making it a less accurate gauge of ongoing user experience.
The Web.dev documentation describes INP as follows:
“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 beneath. A low INP means the page was consistently able to respond quickly to all—or the vast majority—of user interactions.”
Where FID focused on the first impression of interactivity, INP takes a broader view, summarizing how responsive a page is across multiple interactions. This more holistic approach gives a better sense of whether users are likely to experience delays during any interaction with the page.
New scoring thresholds for INP: Good, needs improvement, and poor
A key part of the recent documentation update explains the scoring thresholds for INP. Google assigns INP scores into three categories:
- Good: An INP score of less than 200 milliseconds (ms)
- Needs Improvement: An INP score between 200 ms and 500 ms
- Poor: An INP score of more than 500 ms
These scoring bands are based on the principle that an INP of 200 ms or less represents an ideal user experience where interactions feel nearly instantaneous.
However, a score that falls between 200 and 500 ms suggests there’s room for optimization.
Anything above 500 ms is deemed unsatisfactory, indicating a page that is likely slow to respond, negatively impacting user experience.
Why is INP scoring based on mobile performance?
One important detail clarified in the update is why INP thresholds are the same across both desktop and mobile devices.
Initially, it might make sense to use different scores for each, given the differences in network speed and device performance between mobile and desktop. However, as the updated documentation states, Google chose a uniform threshold to reflect user expectations of performance, regardless of the device:
“Mobile and desktop usage typically have very different characteristics as to device capabilities and network reliability… However, users’ expectations of a good or poor experience is not dependent on device… The same threshold is used for both. This also has the added benefit of making the thresholds simpler to understand.”
This means that while INP scores are determined with mobile devices in mind, they apply to both desktop and mobile alike.
Mobile represents the majority of web traffic for most sites, and users expect a seamless experience across devices. By basing the scoring on mobile criteria, Google has set a standard that’s realistic yet challenging for the average mobile user experience.
Consideration for lower-end devices
A significant part of Google’s effort in setting these thresholds was aimed at ensuring that they remain achievable for lower-end mobile devices, which are commonly used for web access. Devices with slower processing speeds or limited network connectivity can struggle to keep up with the demands of modern websites, and setting the threshold too low would make it unattainable for many.
As explained in the documentation:
“We also spent extra attention looking at achievability of passing INP for lower-end mobile devices, where those formed a high proportion of visits to sites… Taking into consideration the 100 ms threshold supported by research into the quality of experience and the achievability criteria, we conclude that 200 ms is a reasonable threshold for good experiences.”
While high-end devices can easily meet these standards, the majority of users with mid-range or budget devices would find it challenging if thresholds were set too aggressively. Therefore, Google set a “good” threshold at 200 ms to balance quality and achievability for the average mobile experience.
How the top websites influenced INP thresholds
Another key aspect in setting the INP thresholds was Google’s analysis of real-world user data from the top 10,000 websites, which account for a major share of internet traffic. By studying the INP scores of these popular sites, Google was able to identify what thresholds were realistically achievable.
The data revealed that if the threshold for a “poor” experience were set at 300 ms, a majority of popular sites would fall into this category. This was a red flag since the Core Web Vitals metrics aim to reflect reasonable, achievable goals that aren’t beyond the reach of many sites.
The final thresholds—200 ms for a “good” experience and 500 ms for a “poor” one—are based on balancing quality and the reality of what top-performing sites could consistently achieve.
The documentation elaborates on this finding:
“When we look at the top 10,000 sites—which form the vast majority of internet browsing—we see a more complex picture emerge… On mobile, a 300 ms ‘poor’ threshold would classify the majority of popular sites as ‘poor’… a 200 ms ‘good’ threshold is also tougher for these sites, but with 23% of sites still passing this on mobile this still passes our 10% minimum pass rate criteria.”
Why the INP threshold update matters
For site owners and developers, these updates to INP scoring criteria mean clearer goals when optimizing for Core Web Vitals. Given that INP will likely play a role in search rankings as part of the Core Web Vitals, sites now have a roadmap for achieving and maintaining a high-performance score across devices.
Barry Pollard, a Web Performance Developer Advocate for Google Chrome and co-author of the documentation, shared insights on the challenges posed by low-end devices and the gradual improvements in INP scores:
“We’ve made amazing strides on INP in the last year. Much more than we could have hoped for. But less than 200ms is going to be very tough on low-end mobile devices for some time. While high-end mobile devices are absolute power horses now, the low-end is not increasing at anywhere near that rate…”
Final thoughts on improving your INP score
Improving INP is all about optimizing responsiveness, particularly for users on mobile devices. Here are some quick tips to ensure your site delivers an engaging and smooth experience:
- Minimize JavaScript: Reduce or defer non-essential JavaScript to limit the time browsers spend processing it.
- Optimize images and videos: High-quality media can slow loading times; compress and delay loading to enhance responsiveness.
- Use modern frameworks: Frameworks like React or Vue offer features that can help manage and minimize response times.
- Limit third-party scripts: Unnecessary third-party scripts can create lags, so keep only essential integrations.
- Enable lazy loading: Load only visible elements at first and delay others until they’re needed.
By focusing on these improvements, site owners can stay competitive with INP standards and provide an experience that keeps users engaged.
This recent update from Google is a reminder of the growing emphasis on creating a fast, responsive web experience for everyone—whether they’re on a high-powered device or an entry-level smartphone.
As Core Web Vitals continue to shape SEO, optimizing for INP will be a smart step toward meeting evolving user expectations.
You can read the updated documentation here. And you can test the Core Web Vital scores of your website using our tools for free.
