Key Takeaways:
- INP measures response time to all user interactions throughout the entire visit
- A good INP value is under 200 milliseconds
- The most common causes are too much JavaScript and slow third-party scripts
Have you noticed red warnings in Google Search Console recently? Since March 2024, there's a new Core Web Vital that has caught many websites off guard: INP. The metric replaces FID and is significantly stricter.
The good news: INP problems can often be fixed without developers. The bad news: Ignoring them is not an option. Core Web Vitals affect your rankings, and INP is now part of the equation. This article explains what the metric measures and how you can improve your value.
What INP Measures and Why It Matters
INP stands for Interaction to Next Paint. The metric measures how quickly your website responds to user actions. When someone clicks a button, opens a menu, or selects a form field, they expect an immediate response. Any noticeable delay frustrates.
The predecessor FID only measured the first interaction on a page. This was inaccurate because a website could respond quickly to the first action but become slow with later interactions. INP captures all interactions throughout the entire visit and takes the worst value. This gives a more realistic picture of the actual user experience.
Understanding INP Ratings
| INP Value | Rating | Meaning |
|---|---|---|
| 0-200 ms | Good | Users perceive the site as responsive |
| 200-500 ms | Needs Improvement | Noticeable delay but still acceptable |
| over 500 ms | Poor | Significant delay, frustrates users |
Why Your Website Responds Slowly
The most common cause of poor INP values is too much JavaScript. Modern websites often load dozens of scripts: tracking, analytics, chat widgets, ad networks, social media buttons. Each of these scripts demands browser resources and can delay interactions.
Third-party scripts are particularly problematic. They load from external servers and are not under your control. A slow ad server can slow down your entire website.
Complex animations and transitions also strain the browser. If a click happens during an animation, the browser must process both simultaneously. This leads to delays.
Large DOM structures slow down every interaction. The more HTML elements your page has, the longer the browser takes to process changes. Pages with thousands of elements respond noticeably slower.
Improving INP Without Programming Knowledge
Many improvements can be made yourself without writing code. Here are the most effective measures:
- Disable unnecessary plugins: Each plugin can load scripts that burden the browser
- Reduce social media buttons: Load sharing buttons only when needed or use simple links
- Check chat widgets: Some chat solutions load significant amounts of scripts
- Optimize ad networks: Lazy loading for ads can significantly improve INP
- Simplify animations: Fewer simultaneous animations mean better response times
Check in Google Search Console which pages have INP problems. Often it's specific templates or page types. If all product pages are bad but blog posts are good, the problem is in the product page template.
WordPress and INP
WordPress websites often have INP problems due to poorly programmed themes and too many plugins. With targeted measures, much can be improved.
Radically reduce the number of active plugins. Many website owners have dozens of plugins installed, half of which they don't use. Each plugin can load JavaScript and worsen INP.
Choose a lean theme. Multipurpose themes with many features often load unnecessary scripts on every page. Specialized, lightweight themes like GeneratePress or Astra perform better.
Use a plugin performance profiler like Query Monitor to see which plugins consume the most resources. Often one or two plugins cause most of the problems.
Advanced Optimizations
For technically inclined users, there are further optimization options. JavaScript deferring delays loading scripts until the main content is loaded. This improves initial responsiveness.
Code splitting divides large JavaScript bundles into smaller parts that load on demand. This reduces the initial script amount.
Web workers can offload computationally intensive tasks to a background thread, keeping the main thread free for interactions.
These measures require developer knowledge or professional support but may be necessary for stubborn INP problems.
Measuring Success
Use PageSpeed Insights and Chrome DevTools to check your INP values. PageSpeed shows you the INP value from real user data, Chrome DevTools enable detailed analysis on your own hardware.
Google Search Console aggregates INP data for your entire website. Here you see how many URLs have good, needs improvement, or poor values.
Test again after each change and document the improvement. INP optimization is often an iterative process.
Check your Core Web Vitals with our SEO Analyzer.
Frequently Asked Questions
What is the difference between INP and FID?
FID only measured the delay for the first interaction on a page. INP measures all interactions throughout the entire visit and uses the worst value (the 75th percentile value). This makes INP a more accurate measurement of the actual user experience.
Can a bad INP value hurt my Google ranking?
Yes, INP as part of Core Web Vitals is a ranking factor. The influence is moderate – content quality is more important. But with otherwise equivalent pages, better performance can be decisive. Additionally, INP affects user experience and thus indirectly bounce rates and time on site.
Why do I suddenly have INP warnings even though I haven't changed anything?
Google replaced FID with INP in March 2024. INP is stricter because it measures all interactions instead of just the first. Websites that had good values with FID can fail with INP. The warnings don't mean your website has gotten worse, but that the measurement method has changed.