Optimizing WordPress Websites for Interaction to Next Paint (INP)

Introduction to INP

Interaction to Next Paint (INP) is a key metric in Google’s Core Web Vitals, replacing First Input Delay (FID) in March 2024. INP measures the time from a user’s first interaction until the next visual update, assessing your site’s responsiveness. This metric considers all interactions, not just the first, focusing on the slowest 2% to reflect the worst-case user experience.

Importance of INP

INP impacts user experience and SEO. Fast visual responses enhance user satisfaction and improve search rankings, while slow responses can negatively affect both.

Factors Influencing INP

1. Input Delay: Delays caused by long JavaScript tasks.

2. Processing Time: The time taken to process user input.

3. Presentation Delay: The time to render the next frame after processing.

Causes of High INP

– Long JavaScript tasks exceeding 50 milliseconds.

– Complex or large pages causing layout thrashing.

– Resource-heavy pages.

– Third-party scripts and tools.

– Slow network connections.

Measuring INP

Tools to measure INP include PageSpeed Insights, Chrome DevTools, SpeedVitals Core Web Vitals Checker, and Lighthouse. Both lab data and field data are essential for a comprehensive understanding.

Benchmarks for INP

– Good: 200 milliseconds or less.

– Needs Improvement: 200-500 milliseconds.

– Poor: Above 500 milliseconds.

Improving INP on WordPress

1. General Performance

   – Use reliable hosting.

   – Choose efficient themes and plugins.

   – Minimize plugins and keep them updated.

   – Use caching and compress data.

   – Implement a CDN.

2. Main Thread Availability

   – Break down large JavaScript tasks.

   – Avoid layout thrashing by batching DOM operations.

3. Lazy Loading

   – Delay loading non-critical resources like images and scripts.

4. Optimize JavaScript

   – Remove unnecessary code.

   – Minify JavaScript files.

   – Defer non-critical scripts.

5. Root Causes Analysis

   – Use tools like Lighthouse and PageSpeed Insights to identify specific issues.

Helpful WordPress Plugins for INP

– WP Rocket: Caching and optimization.

– Flying Scripts: Delays non-critical scripts.

– NitroPack: Advanced caching and optimization.

– Asset CleanUp: Minifies JavaScript and delays scripts.

– WP-Optimize: Database cleanup and caching.

– Perfmatters: Efficient performance tasks.

– W3 Total Cache: Detailed control over optimization.

– Autoptimize: Image optimization and minification.

Optimizing WordPress websites for Interaction to Next Paint (INP) is crucial for delivering a responsive and engaging user experience. You can significantly enhance your site’s performance by focusing on efficient hosting, using reliable themes and plugins, minimizing resource-heavy scripts, and implementing effective caching strategies. Regularly monitor your site’s INP using tools like PageSpeed Insights and Chrome DevTools, and make necessary adjustments to maintain optimal performance. Prioritizing INP optimization boosts user satisfaction and improves your site’s SEO, driving more traffic and engagement.

Useful links