Interaction to Next Paint (INP): Why Slow Clicks Cost B2B Websites Leads

Interaction to Next Paint (INP) is the Core Web Vital that measures how quickly a page responds when someone clicks, taps, or types. Google's web.dev guidance rates 200 milliseconds or less at the 75th percentile as good and above 500 milliseconds as poor. On B2B sites, the clicks that matter most sit closest to a lead: forms, pricing toggles, menus.

INP replaced First Input Delay as a Core Web Vital on March 12, 2024 (web.dev), and it is a harder test. First Input Delay timed only the first interaction. INP watches every one, for the whole visit, and reports the slowest.

Interaction to Next Paint measures three delays, and each has its own fix

Every interaction INP records has three parts. The input delay is the wait before any code responds. The processing duration is the time the event handlers take to run. The presentation delay is the time from the end of that code until the browser paints the next frame (web.dev). A slow score tells you a click felt sluggish. The breakdown tells you why.

This matters more than load speed alone suggests. Chrome usage data cited by web.dev shows that 90 percent of a user's time on a page is spent after it loads, which is exactly the window load metrics ignore. Scrolling and hovering do not count toward INP, so the score is driven by deliberate actions such as opening a menu or submitting a form. A full technical review, like the one in our 2026 website audit checklist, should test those actions on the pages that matter.

Mobile is where most sites fail the INP threshold

Desktop passes almost everywhere, and phones do not. The HTTP Archive's 2025 Web Almanac, built on Chrome field data from July 2025, found 97 percent of websites with good INP on desktop against 77 percent on phones, where 21 percent needed improvement and 3 percent were poor (HTTP Archive Web Almanac). Mobile did improve, up from 74 percent in 2024.

Inner pages are the weak spot. The same analysis found 80 percent of mobile home pages with good INP, falling to 69 percent on secondary pages. For a B2B site, secondary pages are the pricing page, the demo request form, and the gated resource, which is where B2B website conversion is won or lost. Only 48 percent of mobile websites passed all three Core Web Vitals.

INP and Google rankings: a real signal with a firm ceiling

Google states plainly that "Core Web Vitals are used by our ranking systems" (Google Search Central), and its Core Web Vitals guide asks site owners to strive for an INP under 200 milliseconds. The same page experience guidance adds that there is no single signal, and that good Core Web Vitals scores do not guarantee top rankings.

Google also says it will show the most relevant content even if the page experience is sub-par. Read together, those statements put INP in its proper place: a tiebreaker among relevant pages, and a direct lever on what visitors do once they arrive. Teams that treat performance as part of technical SEO get both benefits from the same engineering work.

The conversion case for improving INP on lead-generation pages

Responsiveness shows up in revenue. The Milliseconds Make Millions study, commissioned by Google and run by 55 and Deloitte across 37 brand sites and more than 30 million sessions, found that a 0.1 second improvement in mobile site speed lifted retail conversions by 8.4 percent and travel conversions by 10.1 percent. For lead generation sites it recorded a 21.6 percent improvement in users reaching the form submission page (web.dev). The study predates INP and measured older speed metrics, so treat it as evidence that speed pays, and leave INP-specific claims to INP-specific data.

That data exists in the case studies Google publishes. redBus improved INP by 72 percent and reported a 7 percent overall increase in sales (web.dev). The Economic Times cut its origin INP from over 1,000 milliseconds to 257 and saw a 50 percent decrease in bounce rate with a 43 percent uplift in pageviews on topic pages (web.dev).

Five fixes that improve INP on marketing websites

Start with field data, because lab tools cannot tell you which real interactions are slow. Search Console's Core Web Vitals report and PageSpeed Insights both surface Chrome user data. Then reproduce the slow interaction in Chrome DevTools and read which of the three phases dominates. On marketing sites the usual cause is third-party JavaScript: tag managers, chat widgets, testing scripts and consent tools all competing for the main thread at the moment a visitor clicks.

The fixes follow the phases. Break long tasks into smaller ones so the browser can respond between them. Defer or remove tags that do not need to run on interaction. Show visual feedback immediately, before heavy work starts. Keep the DOM small so updates repaint quickly. And fetch less: redBus cut its search results fetch from 30 items to 10, which brought INP from the 870 to 900 millisecond range down to 350 to 370 (web.dev). JavaScript choices affect discoverability too, as our piece on AI crawlers and JavaScript links explains.

Making INP part of how a B2B website ships

INP drifts because websites change weekly. A campaign adds a pixel, sales adds a chat widget, and a quarter later the demo form is slow again. The durable fix is process: a performance budget per page template, a monthly look at field INP for the ten pages that generate most leads, and a rule that no new third-party script ships without an INP check on mobile.

Google's own threshold gives the team a single target to hold: under 200 milliseconds at the 75th percentile (Google Search Central). If your pricing or demo pages sit above it on mobile, we can help you find the slow interactions and fix them; see our client work or start a conversation.