INP: The Core Web Vital That’s Quietly Destroying Your WordPress Rankings
Let me paint you a picture. You’ve spent months obsessing over your Largest Contentful Paint. You’ve compressed every image until they’re basically pixel soup. Your Time to First Byte is chef’s kiss. Then Google rolls out Interaction to Next Paint, and suddenly your “perfectly optimized” WordPress site is failing core web vitals like a student who studied for the wrong exam.
Welcome to 2024, where Google decided we weren’t anxious enough about page speed already.
What Even Is INP? (And Why Should You Care?)
INP measures how long your site takes to respond when someone actually does something. Clicks a button. Taps a menu. Tries to add something to their cart. It’s not about loading anymore. It’s about responsiveness.
Think of it this way. Your site might load in 1.2 seconds, but if that hamburger menu takes 400 milliseconds to open? Google notices. Users notice. Your bounce rate definitely notices.
The INP metric replaced First Input Delay in March 2024, and honestly? It’s way harder to game. FID only measured the first interaction. INP watches everything. Every click. Every tap. Every rage-induced button mash when your mega menu refuses to cooperate.
The WordPress-Specific Problem Nobody Talks About
Here’s where things get spicy. WordPress sites are particularly awful at INP for reasons that have nothing to do with your hosting or theme choice.
The culprits? JavaScript. So much JavaScript.
- That slider plugin you installed three years ago and forgot about
- Analytics scripts fighting each other for attention
- Cookie consent popups blocking the main thread
- Your theme loading jQuery even though it’s 2024
- Contact form plugins that load scripts on every single page
Every one of these competes for your browser’s attention. When a user clicks something, their click gets in line behind whatever JavaScript nonsense is currently hogging resources.
Actually Fixing INP (Not Just Measuring It)
Alright, enough doom and gloom. Let’s fix this mess.
Step 1: Find Your Worst Offenders
Open Chrome DevTools. Go to Performance. Record yourself clicking around your site like an angry user. Look for those long red bars in the main thread. Those are your enemies.
PageSpeed Insights will tell you your INP score, but it won’t tell you why it sucks. The Performance panel will.
Step 2: Defer, Delay, or Delete
For every JavaScript file loading on your pages, ask yourself: does this need to run immediately? The answer is almost always no.
Add defer to scripts that can wait until HTML parsing finishes. Use async for scripts that don’t depend on anything else. Better yet, use a plugin like Flying Scripts to delay non-essential JavaScript until user interaction.
And those scripts that don’t serve any purpose? Aggressive caching strategies won’t save you if you’re loading garbage. Delete the garbage first.
Step 3: Break Up Long Tasks
Any JavaScript task over 50ms is considered a “long task.” Google hates long tasks. Your users hate them more.
If you’re building custom WordPress blocks with React, you already know the pain. Use requestIdleCallback to schedule non-critical work. Split heavy operations into smaller chunks. Let the browser breathe.
Step 4: Stop Loading Everything Everywhere
Contact Form 7 loads its scripts on every page of your site. Every. Single. Page. Your 404 page doesn’t need form validation scripts.
Use Asset CleanUp or Perfmatters to disable scripts where they’re not needed. This alone can shave 100-200ms off your INP score.
Step 5: Optimize Your Images (Yes, Again)
I know you’re tired of hearing about images. But poorly optimized images don’t just slow down loading—they block the main thread during decoding.
Converting to WebP or AVIF reduces file sizes dramatically, which means faster decoding, which means your click handlers aren’t waiting in line behind image processing.
The CSS Side of INP (Everyone Forgets This Part)
JavaScript gets all the blame, but CSS can murder your INP too.
Complex selectors force the browser to recalculate styles on every interaction. That fancy hover effect with twelve nested pseudo-elements? It’s probably causing layout thrashing.
If you’re still using Bootstrap’s utility classes alongside your custom CSS alongside whatever your theme ships, you’re creating selector conflicts the browser has to resolve in real-time. Switching to Tailwind CSS cleaned up my stylesheet bloat more than any other single change.
Quick Wins That Actually Work
In order of impact:
- Remove unused plugins — Not deactivate. Remove.
- Update PHP to 8.2+ — Faster execution means snappier interactions
- Inline critical CSS — Prevents render-blocking on initial interactions
- Use a lightweight theme — GeneratePress and Blocksy are INP-friendly
- Lazy load below-the-fold elements — But not anything interactive!
The Google SEO Reality Check
Here’s the uncomfortable truth about core web vitals and WordPress performance: INP matters less than you think for rankings, but more than you think for users.
Google uses INP as a tiebreaker, not a primary ranking factor. But poor INP directly correlates with conversion rates, bounce rates, and whether people actually complete forms on your site.
While you’re fixing INP, consider adding proper schema markup to your pages. Fast sites with rich snippets tend to outperform fast sites without them.
Stop Chasing Perfect Scores
An INP under 200ms is “good.” Under 500ms is “needs improvement.” Over 500ms is “poor.”
You don’t need a perfect score. You need a score that doesn’t actively hurt your users or your google seo performance. Get under 200ms and move on with your life.
The sites ranking on page one aren’t all hitting perfect INP scores. They’re just not embarrassingly slow. That’s a much more achievable goal.
Now go audit your plugins. Your INP score is probably crying.