How to Easily Remove Unused JavaScript in WordPress? (With & Without Plugin)

A sluggish website can lead to frustrated users, decreased conversions, and lower search engine rankings. One often-overlooked culprit behind slow WordPress websites is unused JavaScript.

When unnecessary scripts are loaded, they unnecessarily consume bandwidth and processing power, slowing down your site’s loading time. Fortunately, WordPress experts can easily identify and remove the unused JavaScript to boost the speed of the website. 

That’s what I will explain through this blog. Let’s begin with how you can identify the unused JS scripts.

How to Identify Unused JavaScript in WordPress?

Before removing them, you need to identify the exact unused JS scripts that are hindering the performance of your WordPress website. To that end, there are several competent tools that would be of help. Let’s see how you can use them to pinpoint these bottlenecks:

PageSpeed Insights

PageSpeed Insights is a powerful tool provided by Google to analyze the performance of your website. It provides actionable recommendations to improve your site’s speed, including identifying unused JavaScript files.

Here’s how you use PageSpeed Insights to identify unused JavaScript:

Step 1: Visit the PageSpeed Insights website.

Step 2: Input the URL of the specific page on your WordPress site you want to analyze.   

Step 3: Run the Analysis by clicking the “Analyze” button.

Step 4: Check the “Diagnostics” section after the analysis is complete.

Step 5: Look for “Reduce Unused JavaScript”. If your website has unused JavaScript, PageSpeed Insights will highlight it under this category.

PageSpeed Insights will list the specific JavaScript files that are considered unused. These files might be from plugins, themes, or third-party scripts that aren’t necessary for all pages or all users.

GTmetrix

GTmetrix is a powerful tool to diagnose website performance issues, including unused JavaScript.

Here’s how you can use it to identify these performance bottlenecks:

Step 1: Visit the GTmetrix website and enter your WordPress site’s URL.

Step 2: Click the “Test Your Site” button to initiate the performance analysis.

Step 3: If there is unused JavaScript hindering the performance, you’ll find the details under “Reduce JavaScript execution time” in the “Top Issues” section.

Step 4: After the test is complete, click on the “Waterfall” tab.

Step 5: Look for the “JS” section in the chart. This will display a list of JavaScript files loaded on your page, along with their load times.

Pay attention to JS files that take a significant amount of time to load. These are potential candidates for removal or optimization. Look for scripts that are not essential for the initial page load or specific page functions. These might be loaded by plugins or themes that are not actively used on every page.

You can also follow the Waterfall chart in Chrome Developer Tool through Inspect > Network. Then reload the page and check the list of resources. Look for JavaScript files that aren’t being used or are partially loaded.

How to Remove Unused JavaScript in WordPress?

Unused JavaScript files can significantly slow down your WordPress website. By removing them, you can improve your site’s performance, leading to faster load times, better user experience, and improved SEO.

Using a Plugin

WordPress plugins make it easy to take care of a range of functionalities whether you want to integrate something or correct something on the website. So installing a WordPress plugin can also help reduce or remove the unused JavaScript.

Some of the best plugins for reducing the unused JS scripts in WordPress include Asset CleanUp and WP Rocket among others.

How to use it?

Step 1: Install and Activate: Install the plugin from the WordPress repository and activate it.

Step 2: Scan Your Website: The plugin will automatically scan your website to identify unused assets.

Step 3: Review and Optimize: Review the list of unused scripts and stylesheets. Disable or remove the ones that are not essential.

Step 4: Configure Settings: Customize the plugin’s settings to fine-tune performance optimization.

These plugins can help you with advanced features like asynchronous loading, deferring scripts, and many more.

Manual Method

Now, it’s understandable if you are not comfortable installing additional plugins on your WordPress website. In that case, the manual method will be much better.

You will need to create a child theme or go ahead with the parent theme (but the changes may fade away after updates).

Here’s how the process will go.

Step 1: After creating the Child theme, open the functions.php file in your WordPress directory structure.

Step 2: Use browser developer tools or performance testing tools to identify the specific scripts you want to remove.

Step 3: Use the following code to remove a script:

function my_remove_scripts() {
    wp_dequeue_script( 'script_handle_name' );
}
add_action( 'wp_enqueue_scripts', 'my_remove_scripts', 20 );

Replace script_handle_name with the actual handle of the script you want to remove. You can find the script handle in the HTML source code of your website or by using browser developer tools.

Step 4: After making changes to the functions.php file, thoroughly test your website to ensure that everything is working as expected. Check for any broken functionality or layout issues.

As you may understand, this process is a little technical. So if you are not comfortable with editing the core files, consult with our expert WordPress developers. But what kind of benefits will it present?

Benefits of Removing Unused JavaScript in WordPress

Removing unused JavaScript from your WordPress website offers several significant benefits:

• Faster Page Load Times: By eliminating unnecessary scripts, your website’s load times are significantly reduced.
• Enhanced User Experience: Faster loading times lead to a better user experience, reducing bounce rates and increasing engagement.
• Higher Search Engine Visibility: Search engines like Google prioritize fast-loading websites. Removing unused JavaScript can positively impact your website’s search visibility.
• Lower Server Costs: Fewer requests and smaller file sizes reduce the load on your server, potentially leading to lower hosting costs.
• Reduced Attack Surface: Fewer scripts mean fewer potential vulnerabilities, making your website more secure.
• Better Mobile Experience: Mobile devices are often resource-constrained. Removing unused JavaScript can improve the performance of your website on mobile devices.

All in all, by reducing the JS scripts, you can ensure a better performance, and in turn, higher search visibility for your WordPress website.

FAQs on Removing Unused JavaScript in WordPress

Let’s Summarize

Unused JavaScript can significantly slow down your WordPress website, leading to higher bounce rates, lower conversions, and poorer search engine visibility.

You can take care of it through plugins like Asset CleanUp or WP Rocket, or the more hands-on manual approach. Remember to test your website thoroughly after making any changes to ensure that everything works as expected.

If you need help with advanced changes for performance boost, get help from our WordPress professionals today!