How To Prepare Your WordPress Website for Google’s INP (Interaction to Next Paint)

The upcoming replacement of FID (First Input Delay) with INP (Interaction to Next Paint) as a Core Web Vital in March 2024 is set to redefine how we gauge user experience.

This shift demands proactive measures to ensure your website continues to deliver exceptional performance.

Understanding INP

INP, short for Interaction to Next Paint, is a metric in web performance analysis that zeroes in on the duration between a user’s input action, such as a click or tap, and the ensuing visual alteration on the screen. It’s a pivotal gauge in assessing the responsiveness and overall user experience of a website or web application.

Achieving an INP under 200 milliseconds typically results in a smooth and responsive user interface. This rapid feedback contributes to a seamless and satisfying user experience. An INP above 500 milliseconds indicates a significant delay between user interaction and visual feedback, leading to a poor user experience. Such delays can frustrate users, create a perception of sluggishness, and potentially drive them away from the site.

INP is essential because it looks at the entire way we interact with a webpage. Unlike FID which mainly focuses on the time between when you do something and the webpage responds, INP follows the path from your action until the screen changes. This covers how long it takes to process, show, and update what you’ve done.

Why INP matters is because it’s all about making the user experience better. It’s about making sure everything feels smooth and you get quick visual feedback. This lines up with the trend of making websites better for users, caring not only about speed but also about how easy it is to use them.

How is INP different from First Input Delay (FID)?

While INP takes into consideration all the page interactions, FID specifically focuses solely on the initial interaction. Furthermore, FID measures the delay in that initial interaction’s response time, not counting the time taken for event handlers or the pause before showing the next frame.

FID measures how quickly the first interaction responds during a page load, aiming for a smooth and fast initial experience. This quick response often sets a positive tone for the page.

On the other hand, INP dives deeper, examining multiple interactions to assess responsiveness more comprehensively. Because it considers a wider range of interactions, INP tends to offer a more dependable measure compared to the narrower focus of FID.

How to optimize a WordPress website for INP?

Even though INP won’t become an official Core Web Vital until March 2024, taking action ahead of time can greatly benefit your WordPress website. Being proactive now offers a head start, letting you tweak your site and steer clear of unexpected issues.

When you optimize early, you’re laying the groundwork for better user experiences. This way, your website will be ready to meet the standards when INP becomes a core metric. Early preparation also means you can make gradual, meaningful changes without feeling rushed or scrambling to meet the deadline.

Optimize critical rendering path

The critical rendering path is the set of steps browsers take to turn HTML, CSS, and JavaScript into what you see on a webpage.

It basically determines how a page looks and forms for users. Streamlining this path means reducing delays in rendering, which results in faster loading times.

Here’s a more detailed breakdown of what happens when someone accesses a website, based on the diagram above:

  1. Network: The process kicks off with the browser fetching resources (HTML, CSS, JavaScript, images, etc.) from the server where the website is hosted.
  2. HTML parsing & DOM: Upon receiving the HTML content, the browser starts parsing it, constructing the Document Object Model (DOM) which represents the structure of the webpage’s elements. This includes text, images, links, and other content.
  3. CSS parsing & CSSOM: Simultaneously, the browser parses the CSS content, generating the CSS Object Model (CSSOM) which contains information about the styling and layout rules applied to the HTML elements.
  4. Render tree: The DOM and CSSOM combine to form the Render Tree, which is a representation of the elements to be displayed on the screen. This tree structure comprises visible content and its associated styles.
  5. JavaScript: Executable JavaScript code, if present, may dynamically modify the DOM or CSSOM. This modification can alter the structure, content, or styles of the page elements.
  6. Render tree: Any changes resulting from JavaScript execution trigger an update to the render Tree. This update reflects the modified structure and styles, potentially impacting what’s rendered on the screen.
  7. Layout: The browser calculates the precise position, size, and arrangement of each element on the page. This process, known as layout or reflow, ensures that elements are correctly positioned relative to each other according to the CSS rules and content flow.
  8. Painting: Once the layout is determined, the browser begins the process of painting pixels on the screen. It renders the visual representation of the webpage, combining the layout, styling, and content to create the final display that users see.

In essence, optimizing each step ensures faster rendering and a smoother user experience.

FastPixel contributes significantly to this optimization by addressing render-blocking resources and enhancing the initial rendering speed through the optimization of CSS, JavaScript, and HTML. Moreover, it leverages a Content Delivery Network (CDN) to efficiently deliver images, easing server loads and expediting delivery times.

Beyond that, FastPixel implements page and browser caching, reducing server processing demands and elevating overall speed. Pairing it with a robust hosting provider can further amplify performance levels.

Prioritize interaction responsiveness

Ensuring swift interaction responsiveness is key to providing a seamless user experience.

JavaScript execution plays a significant role in interaction delays. Optimizing JavaScript involves several strategies:

  • Minification: Optimizing JavaScript files by removing unnecessary characters and spaces can reduce file sizes.
  • Async and defer attributes: Implement the async or defer attributes in your script tags to control when and how scripts are loaded. This can prevent scripts from blocking page rendering and enhance overall performance.
  • Caching: Use a caching plugin to store JavaScript files locally on users’ devices, reducing the need for repeated downloads and improving load times for returning visitors.
  • Code splitting: Break down large JavaScript files into smaller, more manageable chunks. Load only the necessary scripts for specific pages or interactions, reducing unnecessary overhead.

Pick a good hosting solution

Choosing a reliable hosting provider is key. Services like Kinsta, WP Engine, and SiteGround offer performance-tuned hosting specifically designed for WordPress. These providers offer robust server configurations optimized for speed and security, ensuring your site loads quickly and responds promptly to user interactions.

When selecting a hosting provider, consider their infrastructure and support for technologies like caching mechanisms. Managed WordPress hosting services, such as those provided by Kinsta and WP Engine, often include built-in caching solutions tailored for WordPress sites. These mechanisms store frequently accessed site data, reducing the server load and enhancing responsiveness for user interactions.

Additionally, assess the server’s response time, commonly known as Time to First Byte (TTFB). Tools like Pingdom or GTmetrix can help measure this. Optimizing database queries and ensuring efficient execution can significantly improve TTFB, enhancing the overall server response.

Monitor and test performance

Monitoring your website’s performance is akin to maintaining a well-oiled machine.

It ensures your site functions optimally, providing visitors with a smooth and efficient experience. Tools like Lighthouse, PageSpeed Insights, and GTMetrix offer insights into various performance aspects.

Besides, while these tools provide valuable data, user testing brings a qualitative perspective. Interaction delays might not always be apparent through metrics alone. User testing involves real people navigating your website and providing feedback.

Here’s how to approach it:

  1. Define testing objectives: Determine what interactions or aspects of user experience you want to test — navigation, form completion, or specific functionalities — to guide your testing process.
  2. Select testing participants: Identify your target audience and recruit participants to mirror your user demographics. This ensures relevant feedback tailored to your users’ needs.
  3. Gather feedback: Conduct tests using scenarios or tasks and observe how participants interact with your website. Collect their feedback and insights on any delays or challenges they encounter.
  4. Iterate based on feedback: Use the feedback gathered to make iterative improvements to your website, addressing specific interaction delays or pain points highlighted during the testing phase.

End notes

To get ready for INP becoming a big deal for websites, it’s smart to start getting your site in shape. Keep an eye on how your site is doing regularly and make recommended changes as needed.

Being ahead of the game is key. Put your focus on making your site user-friendly and top-notch in today’s changing online world.

The secret to doing great is starting early and keeping up with what users want and what’s expected in the online world.

Check how FastPixel can boost your WordPress site.

Take a brief pause to check the performance of your WordPress site for free and measure the before and after results to see the value FastPixel adds to your site.

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Andrei Alba
Andrei Alba

Andrei Alba is a technical support specialist and wordsmith here at FastPixel. He enjoys helping people understand WordPress through his easily digestible materials.

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