INP: The Core Web Vital 47% of Sites Are Failing

When Google replaced FID with INP in March 2024, almost half the web started failing Core Web Vitals overnight. Sites that had been passing suddenly were not. WordPress sites got hit particularly hard, and the reasons are not what most people think.

Why This Metric Is Different

First Input Delay only measured the delay on your first interaction. Click a button when the page loads, FID measures how long before something happens. After that first click, FID stopped paying attention.

INP measures every interaction throughout your entire session. Every click, tap, and keypress. A site that responds quickly to the first click but bogs down by the tenth now fails where it used to pass. That is a much stricter standard.

Under 200 milliseconds is good. Between 200 and 500 needs improvement. Over 500 is poor. Google looks at the 75th percentile, meaning your site needs to be responsive for most users, not just the ones on fast devices with good connections.

WordPress Has a Particular Problem

In my experience working with WordPress sites, INP failures almost always trace back to the same culprits: too much JavaScript, and JavaScript that runs at the wrong time.

The average WordPress site loads 20 or more plugins, each adding scripts. Many plugins load all their JavaScript on every page even when the functionality is only used on one. jQuery dependencies are especially problematic. Every interaction triggers processing before anything can paint to the screen.

Page builders make it worse. I have seen Elementor drop PageSpeed scores from 93 to 84 on desktop and from 90 to 75 on mobile on otherwise identical sites. Divi regularly scores in the 60s on mobile with load times in the red zone. The visual builders that make WordPress accessible are also what drags down interaction responsiveness.

Third party scripts pile on. Ad networks cause higher blocking time. Analytics tools track every interaction, adding processing before the next paint. Cookie consent banners can trigger massive script loading when users click Accept.

What Most People Get Wrong

The common assumption is that INP is about page load speed. It is not. A page can load quickly and still fail INP if interactions are sluggish after loading. These are different problems with different solutions.

What surprised me is how often the fix is subtraction, not addition. Removing unused plugins, deferring scripts that do not need to run immediately, eliminating render blocking resources. Performance optimization plugins help, but they cannot fix a fundamentally bloated setup.

The other mistake is ignoring mobile. With FID, the desktop to mobile performance gap was relatively small. With INP, the gap is now 11%. Mobile devices with slower processors struggle much more with interaction responsiveness. If you are only testing on desktop, you are missing the problem.

WooCommerce Sites Have It Worse

If you run an online store, every button click matters. Add to cart. Update quantity. Select shipping. Apply coupon. Each interaction needs to feel instant.

Payment gateway API calls, shipping rate calculations, and TLS handshakes all add latency. The checkout process is often where WooCommerce performance falls apart completely. Users click Purchase and nothing seems to happen for half a second. They click again. Now you have duplicate orders or confused customers who abandoned because they thought something was broken.

The Business Case

Google describes Core Web Vitals as a lightweight ranking signal. A fast site with thin content will not outrank slower sites with better content. But the data shows a correlation: pages ranking at position 1 are 10% more likely to pass Core Web Vitals than pages at position 9.

The bigger impact is user behavior. Bounce rates increase by 32% if load times reach 3 seconds. At 5 seconds, bounce probability jumps by 90%. A one second delay causes 7% fewer conversions. Google reports that each one second delay causes retail conversions to fall by 20%.

Users expect interactions to feel instant. When they click and nothing happens, they assume something is broken. They leave. These are not hypothetical scenarios. They are measured impacts on real businesses.

Where Things Stand

WordPress Core Web Vitals pass rates have improved. Mobile pass rates climbed from around 28% in 2023 to roughly 43% now. INP specifically improved from 69% good to 82% good year over year. That sounds encouraging until you compare it to platforms like Wix, which went from 50% to 85%, or Squarespace at 90%.

WordPress powers about 40% of the web. Its improvements have an outsized impact on overall web performance. But WordPress still lags behind most other content management systems on these metrics.

If your site is failing INP, you are not alone. Almost half the web is in the same position. But that also means fixing the problem puts you ahead of nearly half your competition on a metric Google explicitly says matters. That is why we built our optimization plugin to address these specific issues without requiring you to become a performance expert.