Web performance matters. And now there's a brand new metric in town. It's called INP – short for Interaction to Next Paint. Google started using it in Core Web Vitals this year. That makes it super important for SEO and user experience.
INP measures how fast your website responds to user interactions. It's about what happens when someone clicks, taps, or types. Basically, it's all about responsiveness. If your website is slow to react, your INP score will suffer.
But don’t worry. You can fix it. In fact, you can improve your INP score in just 30 days. Let’s break it down into simple steps.
What Is INP Really?
INP is not like other metrics. It doesn’t just look at your page load. Instead, it watches your page while users interact with it. It picks the slowest interaction (or one of the slow ones) and uses that for the score.
That means, even if your site feels snappy 90% of the time, one laggy click can hurt your INP score.
Google says an INP below 200 milliseconds is good. Between 200ms and 500ms needs improvement. Over 500ms? That’s considered poor.
Why Should You Care?
Bad INP = frustrated users + lower rankings.
Good INP = happy users + better SEO + conversions. Simple.
Week 1: Audit and Measure
You can’t fix what you don’t measure. So, let’s start by seeing where you stand.
- Use Chrome User Experience Report (CrUX): Available in tools like PageSpeed Insights.
- Try the INP Debugger: It’s a nice tool that shows which interactions are slow.
- Implement Real User Monitoring (RUM): Tools like Web Vitals JS, New Relic, or SpeedCurve help get the real picture.
Your goal this week: Understand your current INP score and what’s causing delays.
Week 2: Fix the Big Offenders
Usually, a few bad interactions are dragging your score down. Let’s go after them first!
Common INP Killers:
- Heavy JavaScript tasks – Long running scripts block interactions.
- Unnecessary animations – Especially ones tied to user events.
- Large DOM – Too many elements slow things down.
- Slow event handlers – Clicking a button executes a lot of code? Time to clean it up.
Go through your worst offending interactions one by one. Profile them using Chrome DevTools. Use the Performance Panel. Look for long tasks.
Once you find what's slow, try this:
- Split long JavaScript tasks using requestIdleCallback() or setTimeout().
- Defer non-critical scripts.
- Use passive event listeners for scroll and touch events.
- Lazy-load big chunks of UI or third-party content.
Your goal for this week: Fix the top 2–3 problems causing high INP.
Week 3: Improve Event Handling and Responsiveness
Once the major issues are cleaned up, you can go deeper. This week is about smoothing out the experience.
Smarter Event Handling
- Debounce and throttle handlers – Especially for inputs and scroll.
- Remove unnecessary listeners – Don’t attach too many listeners to the same element.
- Use web workers – Move heavy logic to a separate thread.
UI Improvements
- Give instant visual feedback – Even if the task takes time, show something instantly.
- Avoid layout shifts when showing loading spinners or modal boxes.
- Use skeleton screens – It helps user perception of speed.
You don’t always need to make things faster. Sometimes, just making them feel faster is enough.
Measure Again!
After all changes, retest your site. Use the tools from week one. See how your INP score improved. Still slow? Dig deeper.
Week 4: Polish, Automate, and Monitor
This is the final stretch. You’ve done the heavy lifting. Now let’s make sure your site stays fast.
Automate Performance Checks
- Set up a CI pipeline to run Lighthouse CI tests with every commit.
- Use Web Vitals libraries to collect INP from real users.
- Add alerts when your INP exceeds thresholds.
Final Polish Tips:
- Preload assets that are used right after user interaction.
- Use less JavaScript overall – if you don’t need it, lose it.
- Choose fast frameworks like Astro, Svelte, or use islands architecture with React.
Your goal for this week: Make good INP part of your development culture. Not just a one-time fix.
Bonus Tips for INP Success
1. Avoid Long Tasks
Any JavaScript task longer than 50ms can block interaction. Use Web Workers or split your code into smaller chunks.
2. Be Careful With Third-Party Scripts
Analytics, ads, chat widgets – they can hurt INP. Load them lazily or defer them.
3. Stay Updated
INP is new. Best practices are evolving fast. Follow blogs by Google Web Dev and the Chrome team.
Celebrate Your Wins!
Improving performance is hard work. But it pays off.
After 30 days, your INP score should be faster, smoother, and cleaner. That means users are happier, pages are ranking better, and conversions are up.
Ready to show off your fast site? Share your before-and-after INP scores with the world!
Final Thoughts
INP is here to stay. It’s not just a number. It’s how your site feels to the user.
Improved interaction speed builds trust. It makes people want to click, scroll, and come back for more.
So take 30 days and make your site a joy to interact with. The paint will be fast, and your web app will shine.
