INP, short for Interaction to Next Paint, is a web performance metric introduced by Google to measure the overall responsiveness of a page throughout the user’s entire visit. Unlike metrics that focus on isolated events, INP looks at all relevant interactions — clicks, taps and key presses — and returns a value that represents the perceived latency at the worst or nearly worst moment of the browsing experience. In practical terms, INP measures the time between the user’s action and the next visual update of the interface, that is, the moment when the browser is finally able to paint the next frame with the expected feedback.
From an SEO point of view, INP is part of the Core Web Vitals, the set of indicators Google uses as a page experience signal. The metric has progressively replaced First Input Delay, which only considered the first interaction and did not account for responsiveness throughout the page’s lifecycle. For ranking professionals, understanding INP means understanding how interface smoothness influences the perception of site quality and, consequently, organic results.
What INP measures, phase by phase
INP quantifies the delay between a user interaction and the next frame in which the browser shows a visual response. Each interaction is broken down into phases that include waiting in the event queue, running the associated handlers and the presentation phase. The final value is not an average, but a summary that prioritizes the slowest interactions, so as to reflect the worst case perceived by the user.
Why INP goes beyond First Input Delay
First Input Delay measured only the delay of the very first interaction, often a click on an element already visible. INP is more complete because it considers all interactions, including those that happen after several seconds on the page. This makes it more representative of real responsiveness, especially on sites rich in dynamic components.
When an INP value is good
A low INP indicates that the page responds quickly to user actions. Low values suggest a smooth and responsive interface, while high values signal delays that the user perceives as freezes or slowdowns. The reference thresholds published by Google distinguish between good, needs improvement and poor experience.
Google’s rating ranges
Google defines three ranges to classify INP: good, needs improvement and poor. These thresholds help teams set measurable goals and prioritize optimization work. The rating is typically taken at the 75th percentile of data collected from real users.
| Metric | What it measures | Good threshold | Scope of observation |
|---|---|---|---|
| INP | Responsiveness to all interactions | Up to 200 milliseconds | Entire page lifecycle |
| First Input Delay | Delay of the first interaction | Up to 100 milliseconds | Only the first interaction |
| Largest Contentful Paint | Perceived loading speed | Up to 2.5 seconds | Main visible element |
| Cumulative Layout Shift | Visual stability of the page | Up to 0.1 | Unexpected shifts of elements |
The impact of INP on search results
Core Web Vitals are a set of signals that Google evaluates alongside other page experience factors. A high INP can indicate an unresponsive interface, with possible effects on user satisfaction and browsing behavior, such as an increase in bounce rate. Since experience quality is a factor considered in ranking, improving INP is part of a site’s technical optimization work.
Responsiveness and organic performance: the indirect link
A slow interface discourages interaction and reduces time on site, factors that can indirectly influence search results. Moreover, users who perceive delays tend to return to search results to look for alternatives, feeding negative signals of overall satisfaction.
Actions to reduce interaction delays
Optimizing INP means reducing the work the browser has to do while handling interactions. The most common causes of high values are long tasks on the main thread, overly expensive interface updates and resources competing for the same processor attention. Below is a sequence of recommended actions, from the most immediate to the most structural.
- Reduce the duration of tasks that block the main thread by breaking long tasks into smaller units.
- Defer non-urgent activities so that the computing resource is free during interactions.
- Limit rendering work by avoiding unnecessary or redundant visual updates.
- Optimize event handlers by applying event delegation and reducing unnecessary calculations.
- Reduce the weight of style and behavior resources loaded in the initial phase.
- Use lazy loading for components not visible in the first screen.
- Monitor real user data to identify the slowest interactions and intervene in a targeted way.
- Verify improvements with repeated measurements, comparing values before and after changes.
Field data and lab measurements
INP can be detected both in the field, through data collected from real users, and in the lab, through performance analysis tools. Field data offers an authentic picture of the experience, while lab measurements allow you to reproduce and diagnose problems in a controlled way. Integration with analytics platforms and the developer console lets you isolate critical interactions and understand their causes.
Frequently asked questions about INP
What does INP stand for?
INP stands for Interaction to Next Paint and indicates the time between a user interaction and the next visual update of the page.
Has INP replaced First Input Delay?
Yes, INP has progressively taken the place of First Input Delay within the Core Web Vitals, offering a more complete measure of responsiveness.
What is a good INP value?
A value considered good is 200 milliseconds or less, measured at the 75th percentile of data collected from real users.
Does INP directly affect ranking?
INP is a page experience signal evaluated alongside other factors; it does not act alone, but contributes to the overall quality of the user experience.
What are the most common causes of a high INP?
Typical causes include long tasks on the main thread, expensive event handlers and interface updates that require too much rendering work.
How do you verify INP improvement?
You compare field data collected before and after the changes, alongside lab measurements to confirm the reduction of delays in critical interactions.
Facing this issue?Does your site respond slowly to clicks and taps, making INP look high and driving visitors away?A high INP worsens the user experience and can cost you conversions. I analyze interactions and optimize the code to reduce delays.Discover the Core Web Vitals service
Related entries:
Core Web Vitals CLS Core Web Vitals Total Blocking Time FID (First Input Delay) Cumulative Layout Shift