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How To Improve Your First Input Delay on WordPress

April 11, 2023 | By David Selden-Treiman | Filed in: Core Web Vitals.


First Input Delay (FID) is a user experience metric that measures the time it takes for a website to respond to a user’s first interaction, such as a click or tap. To optimize FID, focus on improving website performance by implementing strategies like optimizing code, leveraging browser caching, and optimizing server response time.


Hey there! As you probably know, website speed is incredibly important for both user experience and search engine optimization (SEO). When your website loads quickly, your visitors are more likely to stay, explore, and ultimately convert into customers or subscribers. Plus, search engines like Google prioritize fast-loading websites in their search results, which can help you get more organic traffic.

One key metric you should focus on is the First Input Delay (FID). FID measures the time it takes for your website to respond to a user’s first interaction, such as clicking a button, tapping a link, or typing in a form field. It’s particularly relevant for WordPress websites, as they often rely on plugins and themes that can impact performance.

In this guide, we’ll walk you through the steps to improve your FID on WordPress, ensuring your website is both user-friendly and search engine optimized. Let’s get started!

Assessing Your First Input Delay

Before diving into optimizing your WordPress site, it’s crucial to assess your current First Input Delay (FID). This will give you a clear starting point and help you identify areas that need improvement. There are several tools you can use to measure FID, and we’ll introduce you to three popular ones.

Tools to Measure FID

Google PageSpeed Insights

This is a free tool by Google that analyzes the performance of your website on both mobile and desktop devices. Simply enter your website’s URL, and it will provide you with a detailed report, including your FID score.


Another great option is Lighthouse, an open-source tool by Google that audits your website’s performance, accessibility, SEO, and more. You can access Lighthouse in the Chrome DevTools or as a browser extension.

Chrome User Experience Report

This tool offers real-world user experience data for your website, collected from Chrome users who have opted into sharing their browsing data. It can provide valuable insights into your FID performance across different devices and connection types.

Analyzing FID results

Once you’ve measured your website’s FID using one or more of these tools, it’s time to analyze the results and set improvement goals.

Understanding the Benchmarks for FID

Google recommends aiming for a FID score of 100 milliseconds or less to provide a good user experience. Anything between 100ms and 300ms needs improvement, while scores above 300ms are considered poor.

Identifying Areas that Need Improvement

Review the detailed reports provided by the tools, and take note of any specific issues or recommendations they highlight. These insights will help you focus your optimization efforts and achieve better FID scores.

Now that you have a clear understanding of your current FID performance, let’s explore the steps you can take to improve it on your WordPress website.

Optimizing JavaScript Execution

JavaScript plays a significant role in the performance of your WordPress site, and optimizing its execution can greatly improve your First Input Delay (FID). Here are three key strategies to optimize JavaScript for better FID scores:

Minify JavaScript Files

Definition and Benefits

Minification is the process of removing unnecessary characters (like whitespace, comments, etc.) from your JavaScript files without altering their functionality. This makes the files smaller and faster to download, reducing the time it takes for your site to become interactive.

WordPress Plugins to Minify JS Files

Several plugins can help you minify JavaScript files on your WordPress site, such as Autoptimize, WP Optimize, and W3 Total Cache. Just install your preferred plugin, and follow its instructions to enable JavaScript minification.

Defer Non-Critical JavaScript

How and Why to Defer Javascript

Deferring JavaScript means instructing the browser to load non-critical JS files after the main content has been loaded. This ensures that your site’s main content is displayed quickly, improving FID scores.

WordPress Plugins to Defer JS

Plugins like Autoptimize, and Async JavaScript can help you defer non-critical JavaScript files on your WordPress site. Each plugin has its own settings and options, so be sure to follow the documentation for proper configuration.

Remove Unused JavaScript

Identifying Unused JS

Over time, you might accumulate unused or unnecessary JavaScript files on your site, such as old plugins or themes that are no longer active. These files can still impact your site’s performance, so it’s essential to identify and remove them.

Removing or Commenting Out Unused JS

Once you’ve identified any unused JavaScript files, you can either remove them entirely or comment them out (if you think you might need them in the future). To do this, you can use a plugin like Asset CleanUp or manually edit your theme files, being cautious not to break any functionality.

By following these steps to optimize your site’s JavaScript execution, you’ll be well on your way to improving your First Input Delay and overall website performance.

Leveraging Browser Caching

Browser caching can significantly improve your First Input Delay (FID) and overall site performance. Let’s explore what browser caching is and how to configure it for your WordPress site.

What Is Browser Caching?

Browser caching is the process of storing a copy of your site’s resources (like images, CSS, and JavaScript files) on the visitor’s device. When the visitor returns to your site, their browser can quickly load the cached resources instead of downloading them again, making your site load faster and improving FID.

Configuring Browser Caching in WordPress

There are two main ways to enable browser caching on your WordPress site: editing the .htaccess file or using a caching plugin.

Editing Your .htaccess File

The .htaccess file is a configuration file used by Apache servers. To enable browser caching, you’ll need to add some specific code to this file. Here’s an example of code you can use:

<IfModule mod_expires.c>
  ExpiresActive On
  ExpiresByType image/jpg "access 1 year"
  ExpiresByType image/jpeg "access 1 year"
  ExpiresByType image/gif "access 1 year"
  ExpiresByType image/png "access 1 year"
  ExpiresByType text/css "access 1 month"
  ExpiresByType application/javascript "access 1 month"

This code snippet tells the browser to cache images for one year and CSS and JavaScript files for one month. Adjust the expiration times as needed, and then add the code to your .htaccess file using an FTP client or your web host’s file manager.

Using Caching Plugins

If you’re not comfortable editing the .htaccess file or if you’re on a server that doesn’t use Apache, you can use a WordPress caching plugin to enable browser caching. Popular caching plugins like W3 Total Cache, and WP Super Cache have options to configure browser caching easily.

Setting Appropriate Cache Expiration Times

When configuring browser caching, it’s important to set appropriate expiration times for your site’s resources. As a general rule, static resources like images can have longer expiration times (e.g., one year), while dynamic resources like CSS and JavaScript files should have shorter expiration times (e.g., one week to one month) to ensure that users receive updates when you make changes to your site.

By leveraging browser caching, you’ll make your WordPress site faster and more responsive, leading to better FID scores and a more enjoyable experience for your visitors.

Optimizing Server Response Time

Improving your server response time is essential for enhancing your First Input Delay (FID) and overall website performance. Let’s discuss the importance of server response time and some strategies to optimize it for your WordPress site.

Importance of Server Response Time for FID

Server response time, also known as Time to First Byte (TTFB), is the time it takes for your server to start sending the first byte of data in response to a user’s request. A faster server response time means that your site can start loading sooner, which leads to quicker interactivity and improved FID scores.

Upgrading to a Better Hosting Provider

One of the most effective ways to optimize server response time is to choose a high-quality hosting provider. Here are some factors to consider:

Types of Hosting Services

There are various types of hosting services, such as shared hosting, Virtual Private Servers (VPS), dedicated hosting, and managed WordPress hosting. While shared hosting is often the most affordable option, it can result in slower server response times due to multiple websites sharing the same server resources. Upgrading to VPS or managed WordPress hosting can provide better performance.

Some well-regarded hosting providers that offer WordPress-specific plans include SiteGround, Kinsta, and WP Engine. These providers have optimized server configurations and features designed to improve your WordPress site’s performance.

What Hosting Do We Use?

Here at Potent Pages, we use a highly customized hosting configuration designed for high performance with large volumes of traffic. Our hosting is designed for both the flexibility to handle complex WordPress websites while using server optimizations like file and database caching. If you’d like to use our hosting, please contact us and let us know!

Implementing Server-Level Caching

Server-level caching can help reduce your server’s workload and improve its response time. There are two primary types of server-level caching you can implement:

Object Caching

Object caching stores the results of database queries, so the next time the same query is requested, it can be retrieved from the cache instead of querying the database again. This speeds up the server response time and reduces the load on your database. Popular object caching solutions include Memcached and Redis.

Opcode Caching

Opcode caching stores the compiled PHP code in memory, which reduces the time it takes for the server to process PHP scripts. The most widely-used opcode caching solution is OPcache, which is included with PHP 5.5 and later versions. It’s generally included in most hosting plans.

To implement server-level caching, you might need to consult your hosting provider’s documentation or contact their support team for guidance.

File Caching

File caching is another important aspect of server-level caching that can significantly improve your website’s performance and reduce server load. By storing static files, such as HTML, CSS, JavaScript, and images, in the cache, your server can quickly serve these files to your visitors without having to process them every time.

Advantages of File Caching

File caching can help reduce server resource usage, improve page load times, and contribute to better First Input Delay (FID) scores. By serving static files from the cache, your server can dedicate more resources to handling dynamic content and other tasks.

Configuring File Caching in WordPress

There are several WordPress plugins available that can help you implement file caching on your website. Some popular options include:

  • WP Super Cache: A widely-used caching plugin that generates static HTML files from your dynamic WordPress content. These static files are then served to users, reducing server processing time.
  • W3 Total Cache: Another powerful caching plugin that offers a variety of caching options, including page, database, and object caching. It also provides support for Content Delivery Networks (CDNs) and minification of HTML, CSS, and JavaScript files.
  • WP Rocket: A premium caching plugin that offers a user-friendly interface and a variety of performance optimization features, including file caching, lazy loading of images, and database optimization.

To implement file caching, simply install and activate your preferred caching plugin, then configure the settings according to the plugin’s documentation and your site’s requirements.

By leveraging file caching on your WordPress site, you’ll further optimize server response time, leading to improved FID scores and a better overall user experience.

Regularly Monitoring and Maintaining Your Site

Maintaining and monitoring your WordPress site is crucial for keeping your First Input Delay (FID) and overall performance in tip-top shape. Here are some best practices to ensure your site continues to run smoothly:

Regularly Updating WordPress, Themes, and Plugins

Keeping your WordPress core, themes, and plugins up-to-date is essential for optimal performance and security. Updates often include performance improvements, bug fixes, and new features that can help enhance your site’s FID and overall user experience.

Schedule Regular Updates

Set aside time to regularly check for updates and apply them as needed. You can find available updates in your WordPress dashboard under the “Updates” section. WordPress should be able to handle automatic updates, but be careful since some updates can break your site (in my experience).

If you want to just use automatic updates, be sure to have a backup of your site available in case you need to revert your updates. That’s generally good advice too.

Test Updates in a Staging Environment

Before applying updates to your live site, it’s a good idea to test them in a staging environment. This allows you to identify and fix any potential issues before they affect your site’s performance or functionality.

Performing Routine Site Audits

Regular site audits can help you identify and address performance issues that could be impacting your FID. Use tools like Google PageSpeed Insights, Lighthouse, or Chrome User Experience Report to monitor your site’s performance and make improvements as needed.

Schedule Periodic Audits

Aim to perform site audits at least once a quarter or more frequently if you make significant changes to your site.

Analyze and Address Issues

After each audit, review the findings and prioritize any issues that need attention. Addressing these issues promptly can help prevent performance problems from accumulating and negatively affecting your FID.

Removing Unused Plugins and Themes

Over time, you may accumulate unused plugins and themes that can slow down your site and create security vulnerabilities. Regularly review your site’s plugins and themes, and remove any that are no longer needed.

By regularly monitoring and maintaining your WordPress site, you’ll ensure that it continues to perform well, providing a fast, responsive experience for your visitors and maintaining optimal FID scores.

Optimizing Images and Other Media

Optimizing images and other media on your WordPress site is vital for improving your First Input Delay (FID) and overall website performance. Here are some key strategies for optimizing your site’s media content:

Properly Sizing Images

Using appropriately-sized images for your site is essential for fast load times. Uploading overly large images can slow down your site and negatively impact your FID scores.

Determine the Ideal Dimensions

Consider the layout and design of your site to determine the ideal dimensions for your images. For example, if your content area is 800 pixels wide, there’s no need to upload an image wider than that.

Resize Images Before Uploading

Use an image editing tool like Photoshop or GIMP to resize your images to their ideal dimensions before uploading them to your WordPress site.

Compressing Images

Compressing images can significantly reduce their file size without noticeably affecting their quality, making your site load faster and improving FID.

Lossless vs. Lossy Compression

Lossless compression reduces file size without any loss of quality, while lossy compression may result in a slight reduction in quality for a more significant reduction in file size. Depending on your needs and the type of images you use, you may prefer one method over the other. Webp is usually a good format to use if you want the benefits of both.

WordPress plugins for image compression: Several WordPress plugins can help you compress images automatically when you upload them to your site. Popular options include Smush, EWWW Image Optimizer, and ShortPixel Image Optimizer. Install your preferred plugin and configure the settings to optimize images as you upload them.

Using Lazy Loading

Lazy loading is a technique that defers the loading of images and other media until they’re visible on the user’s screen. This can speed up your site’s initial load time and improve FID. By loading only the media content that’s visible to the user, you reduce the amount of data that needs to be loaded initially, making your site faster and more responsive.

There are several WordPress plugins available to help you implement lazy loading on your site, such as Autoptimize and a3 Lazy Load. Install your preferred plugin and follow the instructions to enable lazy loading for your site’s images and other media.

By optimizing your images and other media content, you’ll ensure that your WordPress site loads quickly and provides a smooth, responsive experience for your visitors, leading to better FID scores and overall performance.


In conclusion, improving your First Input Delay (FID) on your WordPress site is essential for providing a fast, responsive, and enjoyable user experience. By implementing the strategies we’ve discussed, such as optimizing your site’s code, leveraging browser caching, and optimizing your server response time, you’ll see significant improvements in your site’s performance.

Don’t forget to regularly monitor and maintain your site by updating WordPress, themes, and plugins, performing routine site audits, and removing unused plugins and themes. Additionally, pay special attention to optimizing your images and other media by resizing, compressing, and implementing lazy loading.

By following these best practices, you’ll ensure that your WordPress site continues to deliver a top-notch experience for your visitors, leading to better FID scores, increased user satisfaction, and improved search engine rankings. Keep experimenting and refining your optimization efforts to make your site the best it can be. Happy optimizing!

David Selden-Treiman, Director of Operations at Potent Pages.

David Selden-Treiman is Director of Operations and a project manager at Potent Pages. He specializes in custom web crawler development, website optimization, server management, web application development, and custom programming. Working at Potent Pages since 2012 and programming since 2003, David has extensive expertise solving problems using programming for dozens of clients. He also has extensive experience managing and optimizing servers, managing dozens of servers for both Potent Pages and other clients.


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What Is The Best Web Hosting Provider?

Finding the best web hosting provider for your needs is an important step in optimizing your website. There's a lot to consider. Here are our basic recommendations:

Simple Websites

For simple websites, you have a lot of options. Most web hosts will do acceptably for a simple small-business website or blog.

That said, we recommend avoiding website builders so that you maintain control of your website.

VPS Hosting

If you just need a simple VPS, most providers will work well. Different providers have different downtimes, but the big differentiators are cost.

Providers like AWS and Google Cloud tend to be much more expensive than more specialized providers.

We recommend Digital Ocean and Hetzner if you're looking for a good VPS provider at a good price (it's what we use.)

High Performance Hosting

If you're looking for high performance web hosting, you're going to need something more specialized.

You can't just expect a simple cPanel host to give you what you'll need. You need a custom configuration.

Generally, you'll need either a managed host, or you'll need to get your servers configured with custom configurations.

If you're looking for a high performance hosting provider, we offer hosting designed for high-availability and high-traffic.

WordPress Hosting

What WordPress Hosting Should You Get?

There are many considerations when getting a WordPress hosting provider. Focus on the performance needs of your website.

WordPress Hosting Setup

When setting up your WordPress hosting, or switching hosts, there are a number of steps to complete. These include:

WordPress & Security

There are a number of WordPress security threats to contend with. We recommend using a plugin like WordFence to help secure your site.

WordPress Backups

Make sure to also back-up your site. It's absolutely essential, and ideally use an off-site backup provider that's different from your hosting provider.

WordPress Speed Improvements

There are a number of ways to improve the speed of your WordPress site on its hosting.

There are a number of plugins that can help improve your site's speed.


DNS Records

There are many different types of records, each with their own purpose. These include: SOA, A, TXT, CNAME, PTR (reverse DNS), and more. On some servers, you can also set up wildcard records.

The records you need will depend on what you're doing; WordPress sites require different records than mail servers, for example.


The process of your records transmitting to DNS servers around the world is called propagation. It normally takes 48 hours, but you can speed it up a bit with some planning.


To test your DNS records, there are 2 main tools: dig and nslookup. Each is very helpful in its own specialty.

Reliability & Security

There are a number of ways to improve your DNS reliability and security.

  • Split Horizon allows you to separate networks, either for intranets or for separating by geographic region.
  • GeoDNS allows you to give different records to different locations based on the requesting IP address. This allows you to create your own CDN, speeding up your site.
  • DNS over QUIC speeds up your DNS requests and gives you better DNS security by encrypting your DNS connection.
  • DNSSEC allows you to sign and encrypt your DNS connection, ensuring that nobody is changing your records.
  • DNS over HTTPS allows your visitors to request your DNS records over an encrypted connection.

Internationalized Domains

Internationalized domain names allow character encodings other than Latin characters. They have their own methods for backward compatibility.

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