Table of contents
WordPress slow?
We'll sort it out for you!

Improve Interaction to Next Paint (INP) in WordPress

Table of contents

Google leads with the Interaction to Next Paint (INP) will introduce a new evaluation metric from March 2024. In this article, you can find out what the new Web Core Vital means and, above all, what you need to bear in mind to improve the Interaction to Next Paint in WordPress.

What is the Interaction to Next Paint?

The Interaction to Next Paint is Google's new Web Core Vital, which evaluates the general reaction speed of a page to user interactions. Google simulates the click, typing and keyboard behavior of a visitor and measures the longest observed interaction. This is then the value of the INP.

Specifically, you can imagine the measurement using an accordion element on your website. The response time is measured from the time the accordion element is clicked until the content is displayed. If the element opens immediately and displays the content, this is an indication of a good response speed. If the element opens with a delay, for example due to poor code or long animations, the INP deteriorates.

Source: Google - Example of poor response time compared to good response time using an accordion element.

What is a good INP?

As with the other Web Core Vitals, performance is also broken down into three categories here: good response time, response time in need of improvement and poor response time.

The upper measurement limits for the three categories are as follows:

  • Good response time: under 200 ms
  • Response time in need of improvement: Between 200 ms and 500 ms
  • Poor response time: Over 500 ms
Graphic of the broken down metric Interaction to Next Paint

The response time between interaction and content display on your website should therefore always be less than 200 ms in order to pass Google's new measurement metric.

How can I improve the interaction to next Paint in WordPress?

As is so often the case, the interaction to next Paint depends on many different factors. In general, however, you should make sure that your WordPress website always responds quickly and delivers fast server response times. You can find out which steps are necessary for this in detail here:

General performance optimizations

Before we get into the more complex topics, you should make sure that your website generally loads quickly. If this is not yet the case, you should first check your Optimize WordPress pagespeed. In particular, make sure that you have already taken the following optimization measures:

  • Rely on fast WordPress hosting: Fast WordPress hosting improves the overall server response time of your website. The faster the resources (HTML, JavaScript, CSS, MySQL) can be delivered, the better the INP.
  • Deactivate unused WordPress plugins: You should deactivate unused WordPress plugins and, if necessary, reconsider whether you really need every WordPress plugin you use. The fewer plugins you use, the less code needs to be loaded and executed, which ultimately has a positive effect on the responsiveness of your website.
  • Choose a "lean" WordPress theme: When choosing a WordPress theme, you should always make sure that most of the code has been written cleanly and is as lean as possible. Because here too, the less code that needs to be loaded, the better it is for the responsiveness of your website. Currently in vogue are FSE themes. In addition to various advantages such as the block editor, FSE themes are extremely slim in most cases and help you to achieve better loading times.
  • Use a CDN: A content delivery network (CDN) is a network of several servers that can greatly speed up the loading of data-intensive websites. One of the best-known CDNs is Cloudflare.
  • Use a caching plugin: A caching plugin is a must for all WordPress website operators. If you are not yet using a caching plugin, you should change this as soon as possible! With a caching plugin, you can reduce the number of requests to your WordPress website's database and achieve faster response times for your website. According to our tests WP Rocket still probably the best WordPress caching plugin of all time.
  • Keep your WordPress up-to-date: WordPress is constantly being developed and improved. That's why you should WordPress website maintenance should not be neglected. This is the only way to ensure that all load time-relevant innovations also affect your WordPress website.

Minimize and optimize main thread

The main thread is the processing queue of your web browser, so to speak. All website resources relevant to the display are queued and processed one after the other. The less the browser has to process, the faster the response time of your website.

In the WP Rocket caching plugin, you can minimize the main thread with just a few clicks using the file optimization option.

The following measures are the most effective for improving the Interaction to Next Paint in WordPress:

Delay JavaScript execution: You should load JavaScript data with a delay to minimize the load on the main threads. JavaScript data should generally only be loaded once the majority of the relevant and visible content of your website has been loaded. Web developers use the functions setTimeout or requestIdleCallback, for example. If this is too complicated for you, you can fall back on a variety of WordPress plugins that do almost all the work for you. For example, you can use the JavaScript execution delay function of the WordPress caching plugin WP Rocket.

Minimize JavaScript and CSS: Almost every WordPress caching plugin can now also minimize JavaScript and CSS files for you. The aim of minimizing the data is to make the code "lighter" and increase the loading time of these resources. With most caching plugins, this is usually done in the background by removing line breaks, comments and spaces from the code and thus reducing the file size.

Optimize CSS display: You should remove unused CSS from your code or load it asynchronously to speed up the rendering of your website. Some WordPress caching plugin and CDN providers also offer this function. In most cases, CSS rendering can be activated with just one click. But be careful! This is usually a massive intervention in the styling of your website. Your website may then no longer be displayed correctly. Accordingly, you may have to define exceptions for certain CSS files.

Use lazy loading: Lazy loading can significantly minimize the main thread. Thanks to lazy loading, resources such as images or scripts are only loaded when they are in the visible area of the website visitor.

Recommended plugins to improve the Interaction to Next Paint in WordPress

Fortunately, most of the above recommendations can be implemented in WordPress via plugins. To improve the Interaction to Next Paint in just a few clicks, we recommend the following plugins:

  • WP Rocket: While reading this article, you have probably already noticed that we are absolute WP Rocket fans. This is mainly due to the fact that you can implement almost all of the above recommendations (JS & CSS optimization, lazy loading, caching, CDN) and more exclusively with WP Rocket. Accordingly, the caching plugin is our number 1 when it comes to improving the interaction to next paint in WordPress.
  • Asset CleanUpIf you already have a caching plugin that you are satisfied with and would like to make additional optimizations to JavaScript and CSS. Then Asset CleanUp is a great addition.
  • AutoptimizeAutoptimize is also a great addition to the optimization plugins mentioned above to reduce the size of your uploaded images and thus relieve the main thread.
  • NitroPackIs a good alternative to WP Rocket. In contrast to WP Rocket, NitroPack focuses on server-side caching and comes with a CDN as standard.

Conclusion: Improve interaction to Next Paint in WordPress

In WordPress, it is comparatively easy to improve the Interaction to Next Paint, as long as you follow our recommendations above. Basically, it comes down to two things in particular:

  1. Lightning-fast WordPress hosting so that your website can be delivered quickly to improve interaction time.
  2. A good performance optimization plugin like WP Rocket to take the load off the main thread and improve the interaction to next paint.

Tip: With WPspace you get both at once. Lightning fast WordPress hosting + AccelerateWP as a performance plugin. AccelerateWP is a further development of the popular WP Rocket caching plugin and is specially optimized for WPspace servers. In this combination you achieve the fastest loading times and improves the Interaction to Next Paint of your WordPress website.

Picture of David Broll
David Broll
Founder and CEO of WPspace, technology nerd with over 11 years of experience in the IT industry and an absolute WordPress fan.

Links marked with an * are affiliate links. If you buy a product via this link, WPspace receives a small commission. There are no additional costs or disadvantages for you! This has no influence on our opinion of individual products and services - we only recommend what we love ourselves.

Leave a Reply

Your email address will not be published. Required fields are marked *