What is INP and why does it matter for Core Web Vitals?
INP stands for Interaction to Next Paint, and it is the Core Web Vitals metric that measures how quickly your website responds when a visitor clicks, taps or types. Google's target is 200 milliseconds or less. It replaced the older First Input Delay (FID) metric in March 2024, because it gives a much fuller picture of how responsive a page feels over a whole visit.
Why INP replaced FID
FID only measured the delay before the browser first responded to a visitor's first click. That single sample could be misleading. A page might pass FID yet still feel sluggish, because most of the interactions happen after that first one. INP samples every interaction across the life of the page and reports the worst one, which is a far better reflection of what a visitor actually experiences.
INP matters for two reasons. Core Web Vitals have been a ranking factor since 2021, so a slow INP score holds your pages back in Google. Just as important, responsiveness is what visitors feel. A page that ignores clicks feels broken, and people leave quickly when it does.
What a good INP score looks like
Google divides INP scores into three bands:
- Good: 200 milliseconds or less.
- Needs improvement: between 200 and 500 milliseconds.
- Poor: more than 500 milliseconds.
The score appears in the Core Web Vitals section of Google Search Console, and in tools such as Lighthouse and PageSpeed Insights. You can see the same checks in our free SEO report, which flags responsiveness issues alongside the other things Google weighs.
What makes INP slow
INP goes slow when the browser's main thread is too busy to respond. The main thread is where the browser does most of its work: running JavaScript, painting the page and handling user input. When it is tied up with a long task, your clicks and taps queue up behind it. The usual culprits are:
- Heavy JavaScript that runs on page load.
- Third-party scripts such as chat widgets, tracking pixels and embedded video players.
- Event handlers that do too much work on the main thread.
- Large, unoptimised images that force the browser to work harder.
How to improve INP
The fixes follow a clear order. Cut JavaScript that is not essential, and load third-party scripts only where they add real value. Defer anything that does not need to run immediately, so the page can respond to the visitor first. Break long tasks into smaller chunks, and move heavy work such as data processing off the main thread where you can. Finally, simplify event handlers so a single click does not trigger a cascade of work.
The hardest part is knowing which of these is hurting your page, which is why we start every engagement with a technical audit. We measure the page, identify the specific causes of a slow INP, and fix the highest-impact items first. It is the same process that sits behind results such as the 251 per cent growth in organic traffic Home Instead achieved with us.
Where INP fits in the bigger picture
INP is one of three Core Web Vitals, and our separate guide explains the full set, including loading speed and visual stability. Responsiveness is often the easiest of the three to improve once you know what is causing it, and a passing score is well within reach for most small business sites. If you would like us to audit yours, our technical SEO service covers the full Core Web Vitals check, the fixes and ongoing monitoring. See what it includes at https://victory.digital/technical-seo.
Not sure where your site stands? Run a free SEO report and see the issues Google would flag, at https://victory.digital/run-a-seo-report.
What are your Feelings?
Share your reaction
Click a reaction to share how useful this article was.