You tap "Add to Cart" on your phone and nothing happens for a second or two. You click a mobile menu and it just sits there. That frustrating lag has a name Google now uses to judge every website: Interaction to Next Paint, or INP. If you've heard the term but aren't sure what it measures or why it matters for your business, this guide explains it in plain English.
What Is Interaction to Next Paint (INP)?
INP measures how quickly your website visibly responds after someone interacts with it — a click, a tap, or a key press. It's not about how fast your page loads in the first place, but about what happens every time a visitor tries to do something on that page: open a menu, submit a form, tap a product image, or type into a search box.
Google times the gap between the interaction and the moment the browser visibly paints a response on screen. Do that quickly and consistently across a visit, and INP is good. Make people wait — even briefly — and INP suffers, no matter how fast your homepage first appeared. That's a genuine shift from older speed metrics, which were mostly about how fast content first appeared, not how the site behaves once someone is actually trying to use it — a distinction we unpack more broadly in why website speed matters.
Why INP Replaced First Input Delay
INP took over from First Input Delay (FID) as an official Core Web Vital in March 2024. FID only measured the delay before the browser started processing the very first click or tap on a page — a narrow, one-off snapshot that said nothing about any interaction after that.
INP is far more honest. It looks at responsiveness across the entire visit, not just the opening click. If your mobile menu opens instantly but your booking form freezes for a moment when someone hits "submit," FID would never have caught that. INP does, because it's measuring the interactions that actually matter to a visitor trying to get something done on your site.
Why a Slow INP Score Costs You Customers
Think about how it feels when an app or website doesn't respond to your tap. You tap again, nothing changes, so you assume it's broken and give up or go elsewhere. That hesitation is exactly what a poor INP score represents, multiplied across every visitor who tries to interact with your site.
For a small business, this plays out in very concrete ways:
- A Newcastle electrician's online booking form takes a visible beat to respond after a customer selects a time slot, so they tap again, the form double-submits, and the confused customer rings a competitor instead.
- A Perth online store's "Add to Cart" button feels laggy on mobile — the customer isn't sure it worked, taps it twice, ends up with two of the same item in their cart, and loses confidence in checking out.
- A law firm's contact form seems unresponsive after a visitor clicks "send enquiry," so they close the tab assuming it failed, and the enquiry never arrives.
None of these visitors will tell you why they left. They simply assume the site is broken or untrustworthy and go elsewhere — precisely the kind of invisible leak we cover in why your website isn't generating leads.
What Causes Poor INP on Small Business Websites
INP problems almost always come down to the browser being too busy to respond instantly when someone interacts with the page. Common causes on small business websites include:
- Too many plugins and scripts. Every plugin adds JavaScript the browser has to run. Stack up a dozen and the browser can be busy processing all of them right when a visitor clicks something.
- Bloated page builders. Drag-and-drop builders are convenient but often generate heavy, inefficient code to render fairly simple layouts.
- Third-party trackers and chat widgets. Analytics tags, marketing pixels and live chat widgets often run scripts continuously in the background, competing with your visitor's click for attention.
- Large, unoptimised images. Oversized images still consume browser resources as they're decoded, which can delay how quickly the page responds to other things happening at once.
- Poorly coded animations and effects. Hover effects, sliders and scroll animations that aren't coded efficiently can tie up the browser exactly when a visitor tries to click something else.
Individually, each cause might only cost a fraction of a second. Together, on a typical plugin-heavy small business site, they add up to the noticeable lag that makes a website feel clunky and unreliable.
INP Causes vs Fixes at a Glance
| Common Cause | Practical Fix |
|---|---|
| Too many plugins | Audit and remove plugins you don't actually use; keep only what earns its place |
| Bloated page builder | Choose a lighter theme or builder, or simplify complex page layouts |
| Chat widgets and trackers | Defer them so they load only after the page becomes interactive |
| Unoptimised images | Compress and resize images so they don't compete for browser resources |
| Heavy custom animations | Simplify effects or have a developer make the underlying code more efficient |
| Long JavaScript tasks | Ask a developer to break large scripts into smaller chunks the browser can interrupt |
How to Improve Your INP Score
You don't need to be a developer to make real progress on INP. Start with these practical steps:
- Audit your plugins. List every plugin on your site and honestly ask whether it earns its keep. Deactivate and delete anything you're not actively using.
- Defer non-essential scripts. Chat widgets, review pop-ups, marketing pixels and social media embeds rarely need to load the instant the page opens. Loading them a moment after the page becomes interactive keeps the browser free for what your visitor is actually doing.
- Choose lighter themes and builders. A lean, well-coded WordPress theme will consistently outperform a heavy, feature-stuffed one. This matters even more if you're overdue for a refresh — see our signs you need a website redesign guide.
- Optimise your images. Compress and correctly size every image so it isn't larger than it needs to be, using our image optimisation guide as a starting point.
- Simplify heavy animations. If a section of your site has elaborate hover effects or scroll animations, ask whether it's worth the responsiveness trade-off.
- Work with a developer on long JavaScript tasks. This is where a developer earns their fee — breaking long-running scripts into smaller pieces so the browser can respond to a click even while other work happens in the background. Our speed up WordPress website and render-blocking resources guides cover closely related fixes worth tackling at the same time.
Checking Your INP Score in Google PageSpeed Insights
You can check your own site's INP for free using Google PageSpeed Insights. Enter your website's address and it will report your Core Web Vitals, including INP, based on real visitor data where enough traffic exists, plus a lab test you can run on demand.
Google's published guidance gives you a clear yardstick:
- Good: 200 milliseconds or less
- Needs improvement: between 200 and 500 milliseconds
- Poor: over 500 milliseconds
Test your homepage and a page with genuine interactions, like a contact form or product page, since that's where INP problems tend to show up. For the full picture of how INP fits alongside the other Core Web Vitals, see our Google Core Web Vitals guide.
Key Takeaways
- INP measures how quickly your site visibly responds to clicks, taps and typing — across the whole visit, not just the first interaction.
- INP replaced First Input Delay as an official Core Web Vital in March 2024 because it measures real, ongoing responsiveness rather than a single first click.
- Google considers 200 milliseconds or less good, and over 500 milliseconds poor.
- Common causes are too many plugins, bloated page builders, third-party scripts, unoptimised images and heavy animations.
- Many fixes — auditing plugins, deferring widgets, compressing images — don't require a developer, though breaking up long scripts does.
Frequently Asked Questions
What is a good INP score?
Google considers 200 milliseconds or less a good INP score, 200 to 500 milliseconds needs improvement, and anything over 500 milliseconds is poor. Check your own site's score for free in Google PageSpeed Insights.
Is INP the same as page load speed?
No. Page load speed measures how quickly content first appears, while INP measures how quickly the page responds to interactions after it has loaded, such as clicking a button or submitting a form. A site can load fast and still have a poor INP if it feels sluggish to use.
Why did Google replace First Input Delay with INP?
First Input Delay only measured the delay before a browser processed the very first click on a page — a narrow, one-off snapshot. INP measures responsiveness across every interaction during a visit, giving a far more honest picture of whether a site feels responsive.
Can plugins really affect my INP score?
Yes. Each plugin typically adds JavaScript the browser has to load and run. A handful is rarely a problem, but a site running a dozen or more, especially ones running continuously in the background, can make the browser too busy to respond instantly when a visitor clicks something.
Do chat widgets and tracking scripts hurt INP?
They can. Chat widgets, marketing pixels and analytics trackers often run scripts in the background that compete with your visitor's interactions for the browser's attention. Loading them a moment after the page becomes interactive, rather than immediately, generally solves this without losing their functionality.
How do I fix a poor INP score without a developer?
Start by auditing and removing unnecessary plugins, deferring chat widgets and trackers, compressing your images, and simplifying heavy animations. These steps often make a noticeable difference on their own, though breaking up long JavaScript tasks is usually best left to a developer.
Does INP affect my Google rankings?
Core Web Vitals, including INP, are one of many signals Google factors into ranking. More importantly, a poor INP directly affects how visitors experience your site — a laggy "Add to Cart" button or booking form costs enquiries and sales regardless of where you rank.
Get a Website That Responds Instantly
A website that looks great but hesitates every time someone clicks is quietly costing you enquiries and sales. If you'd like your site properly assessed for INP and the other Core Web Vitals, and fixed by people who understand exactly what's slowing it down, have a chat with Pixel and Pine. We build and maintain websites that respond the instant your customers ask them to.
