Interaction to Next Paint (INP) is the Core Web Vitals measure of responsiveness. It looks at how long the page takes to show a visual response after a visitor clicks, taps or presses a key, and reports roughly the slowest interaction of the visit. An INP of 200 milliseconds or less, at the 75th percentile, is rated good.
Why it matters
A page can load fast and still feel stuck if a menu opens late or a button seems to ignore your tap. INP captures that feeling. It replaced First Input Delay (FID) as a Core Web Vital in March 2024, because FID only looked at the first interaction and only at the wait before processing began.
Each interaction is made of three phases:
- Input delay: the wait before the browser can start running your code, often because the main thread is busy.
- Processing time: how long your event handlers take to run.
- Presentation delay: the time for the browser to draw the next frame.
INP counts clicks, taps and keyboard presses. Scrolling and hovering are not part of it. On pages with many interactions, a small number of extreme outliers are ignored.
How to check
- Open PageSpeed Insights and read the field data block at the top. If enough real-visitor data exists, it shows INP for your page or origin.
- Use the Core Web Vitals report in Search Console to find URL groups rated poor or needing improvement.
- In Chrome DevTools, open the Performance panel, interact with the page while recording and look at the Interactions track for slow entries.
- Lighthouse reports Total Blocking Time, which is a lab signal that often tracks with poor INP, but it is not the same metric.
Rating bands for INP:
| INP | Rating |
|---|---|
| 200 ms or less | Good |
| Over 200 up to 500 ms | Needs improvement |
| Over 500 ms | Poor |
Common mistakes
- Relying on a lab test alone. INP depends on what real visitors click, so field data is the reliable source.
- Only testing the first click, which is what FID used to reward.
- Leaving heavy third-party scripts such as chat widgets and tag managers running on the main thread.
- Running one long function inside an event handler instead of splitting work into smaller tasks.
Frequently asked questions
What is a good INP score?
200 milliseconds or less, at the 75th percentile of page loads, is good. Between 200 and 500 milliseconds needs improvement, and above 500 milliseconds is poor.
Is INP the same as page speed?
No. Page speed usually refers to loading, which LCP measures. INP is about how the page behaves once it is loaded and someone starts using it.
Why is INP missing for my site?
Field metrics need enough real traffic from supported browsers. Low-traffic pages may show no INP value, in which case lab profiling is the fallback.
Related guides
- Improve Interaction to Next Paint
- Core Web Vitals explained
- Reduce JavaScript bundle size
- Third-party scripts and performance
Crawvix's scan checks whether interaction responsiveness (INP) is good. To see where your site stands, Try the free website sample.