A slow website frustrates visitors and negatively impacts your business. When pages take too long to load, users leave, and your search engine rankings decline.
The underlying issue often lies in unused CSS code that clutters your theme and plugins. This unnecessary code increases the load on your pages without providing any benefit.
We have optimized hundreds of WordPress sites for speed, and we’ve discovered that eliminating this code significantly enhances performance. It helps your site meet Core Web Vitals standards and improves the overall user experience.
In this guide, we will demonstrate how to remove unused CSS in WordPress to enhance your site’s speed.
What Is Unused CSS in WordPress?
Unused CSS in WordPress is the CSS code that gets loaded on your web pages but is not utilized to style any visible elements on those specific pages.
This excess code forces visitors’ browsers to download and process unnecessary files, which slows down page loading times. Even a few extra seconds can negatively affect user experience and search engine rankings, potentially leading to lost visitors and conversions.
You can easily determine if unused CSS is impacting your site by using Google PageSpeed Insights. Look for the ‘Remove unused CSS’ warning in your results, which will indicate exactly which files are causing slowdowns.
Understanding Why WordPress Loads Unused CSS
WordPress is not selective about the CSS it loads. Each WordPress theme includes a primary stylesheet, typically named style.css, which contains styles for every element, including those you may never utilize.
Your theme is only the starting point. Each plugin you add contributes its own CSS files. For instance, WooCommerce applies shop styles across all pages, including blog posts, page builders apply their CSS site-wide, and contact form plugins inject styles even on pages without forms.
When you factor in custom fonts, icon libraries, and other design components, the amount of CSS can become excessive. Although each file may be small, they accumulate quickly and can negatively affect your website’s loading speed.
Steps to Eliminate Unused CSS in WordPress
The good news is that there are several effective strategies to remove unused CSS from your WordPress site. We have tested various methods and identified reliable solutions that won’t disrupt your website’s functionality.
It’s important to note that completely removing all unused CSS is nearly impossible because of how WordPress dynamically loads content. Some CSS must remain available for interactive features, conditional content, and various page formats.
Don’t worry; you don’t need to achieve perfection to see significant improvements. Even removing 50-70% of unused CSS can greatly enhance your site’s speed.
We will present two effective methods that balance performance enhancements with site stability, allowing you to select the approach that suits your comfort level.
- How to Remove Unused CSS in WordPress with WP Rocket
- How to Remove Unused CSS in WordPress with Asset CleanUp
- Common Questions About Unused CSS
- Extra Resources for Enhancing WordPress Performance
Step 1: Remove Unused CSS in WordPress with WP Rocket
This method is user-friendly and ideal for beginners. It significantly enhances the delivery of CSS files on your WordPress site by eliminating most unused CSS.
We believe this is the best option for beginners due to its simplicity and effectiveness in achieving a better user experience. This means your website will load quickly on speed tests and feel fast for your visitors.
First, install and activate the WP Rocket plugin. Although it’s a premium plugin, it offers the easiest solution for those without technical expertise. For detailed instructions, refer to our step-by-step guide on installing a WordPress plugin.
After activating the plugin, navigate to the Settings » WP Rocket section and select the ‘File Optimization’ tab.
Scroll down to the CSS Files section and check the box next to the ‘Remove Unused CSS’ option.
Upon checking the box, a confirmation message may appear. Click the ‘Activate Remove Unused CSS’ button to proceed.
Once activated, you will see a ‘CSS safelist’ box. This feature allows you to specify any CSS filenames, IDs, or classes that should be preserved. Use this if you notice any issues with your site’s appearance after enabling the setting.
Simply input the necessary items into the box.
Next, save your changes by scrolling down and clicking the ‘Save Changes’ button.
After saving, WP Rocket will begin processing your CSS files, and a progress bar will be displayed.
The plugin will take a few minutes to process and eliminate unused CSS files from your website.
You will receive a ‘Remove Unused CSS is complete!’ message once the plugin finishes the process.
Now, go to the Google Pagespeed Insights tool to evaluate your site’s performance.
Alternative: Optimize CSS Delivery (Fallback Method)
If the ‘Remove Unused CSS’ method mentioned earlier is effective for your website,you can skip this step.It takes care of render-blocking CSS for you.
However, if the previous method disrupted your site’s layout and you had to turn it off, you can opt for the ‘Optimize CSS delivery’ feature as an alternative.
To activate this, simply check the box next to the ‘Optimize CSS delivery’ option in the CSS Files section.
This feature creates a CSS file that includes only the styles necessary for displaying the visible portion of your website. It loads this file first, allowing your page to be shown to visitors quickly, and then loads additional CSS files using a technique called deferred loading.
By eliminating this render-blocking CSS, your website becomes accessible to users much faster than if all CSS files had to load before the page is shown.
After enabling the ‘Optimize CSS delivery’ option, click the ‘Save Changes’ button and wait for WP Rocket to create the required CSS file for all your posts and pages. It will also automatically clear your website’s cache.
Once completed, you can test your website’s performance again using Google PageSpeed Insights.
Additional File Delivery Adjustments to Enhance Performance
WP Rocket enables you to eliminate query strings from static files, merge Google Fonts files, and compress HTML.
These optimizations contribute to minor enhancements in your site’s speed, culminating in a quicker loading experience for your audience.
You will find options to compress and merge CSS files, which will minimize HTTP requests and provide an extra speed enhancement.
It’s essential to thoroughly review your website after activating these settings to ensure everything functions correctly.
You can also implement similar optimizations for JavaScript files on your site.
By compressing and merging JavaScript files into a single file and deferring their loading, you can further enhance performance.
For comprehensive instructions, refer to our detailed tutorial on setting up WP Rocket in WordPress effectively.
Method 2: Eliminate Unused CSS in WordPress Using Asset CleanUp
This approach utilizes the free Asset CleanUp plugin. While it requires a bit more manual effort, it gives you complete control to remove specific unused CSS from any page on your WordPress site.
We suggest this method if you are comfortable with troubleshooting your site, as you will need to conduct thorough tests to ensure everything is functioning properly.
Begin by installing and activating the Asset Cleanup plugin. For detailed instructions, refer to our comprehensive guide on how to install a WordPress plugin.
Once activated, navigate to the Asset CleanUp » Settings page and select the Test Mode tab. Here, enable the ‘Enable Test Mode’ option.
This feature allows you to experiment with various settings and test them as an administrator without impacting your website visitors.
Next, go to the Asset CleanUp » CSS/JS Manager page. This is where you can unload unnecessary CSS and JavaScript files on a per-page basis.
Depending on your configuration, it may automatically retrieve and analyze your homepage, displaying a list of all CSS and JavaScript files loaded on that page.
Scroll down to review the loaded files. If you identify a file that is not needed, you can unload it for that specific page, post type, or sitewide.
The plugin also gives you the option to select specific posts or pages, or you can access the same settings by editing the post or page as you usually would.
On the post editing screen, you will find the Asset CleanUp box located just below the post editor.
The plugin automatically retrieves and displays all files and assets that load when a visitor accesses this page on your website.
You can easily deactivate any unnecessary CSS or JavaScript files that are not required for that specific page.
Important:Make sure to test your website after removing any unused CSS or JavaScript to ensure everything functions correctly.
After you have finished deactivating and removing unused CSS and JavaScript files, return to the plugin’s settings page and disable the ‘Test Mode’.
Remember to click the ‘Update All Settings’ button to save your changes.
You can now evaluate your website’s performance using Google PageSpeed Insights to observe the reduction in unused CSS notifications.
Frequently Asked Questions About Unused CSS
Many readers inquire about the safety and effects of cleaning up their stylesheets. Here are answers to some of the most frequently asked questions regarding the removal of unused CSS in WordPress.
1. Is it safe to remove unused CSS in WordPress?
Generally, removing unused CSS is safe if you utilize a trusted plugin like WP Rocket or Asset CleanUp. These tools strive to retain the essential code necessary for your site’s proper appearance. However, due to the complexity of styling, there is always a slight risk of disrupting the layout.
We highly recommend using a backup plugin such as Duplicator to securely save your website before making any changes.
2. Why is it impossible to eliminate all unused CSS?
It is nearly impossible to eliminate every line of unused CSS because WordPress generates pages dynamically.
Some styles remain hidden until a specific action occurs, like a mobile menu sliding out or a popup appearing. If you remove this ‘unused’ code, those interactive features will cease to function.
If a plugin were to eliminate all CSS that isn’t immediately visible, it could disrupt the functionality of interactive features on your WordPress site.
3. Does removing unused CSS contribute to better SEO rankings?
Yes, eliminating unused CSS can enhance your WordPress SEO rankings. Search engines like Google take page speed into account as a ranking factor. By reducing the size of your CSS files, your web pages will load more quickly, indicating to Google that your site provides a positive user experience.
4. Is it possible to manually remove unused CSS without using a plugin?
We do not advise attempting to manually remove unused CSS unless you are a skilled developer. You would need to locate and delete specific lines of code from your theme and plugin files.
Be cautious when manually editing these files, as mistakes can disrupt the design of your entire WordPress site.
Explore More Resources for Enhancing WordPress Performance
We hope this guide has helped you understand how to effectively remove unused CSS in WordPress. You might also find these additional resources on improving WordPress performance helpful:
- The Comprehensive Guide to Enhancing WordPress Speed and Performance
- Tips for Optimizing WooCommerce Performance
- A Step-by-Step Guide to Conducting Website Speed Tests (Top Tools)
- Key Metrics to Track on Your WordPress Website
- The Ultimate Guide to Optimizing Core Web Vitals for WordPress
- Using the GTmetrix Plugin to Enhance WordPress Site Performance
- Simple Ways to Optimize WordPress CSS Delivery
- Top Fastest WordPress Hosting Options (Performance Evaluations)
- How to Optimize Images for Web Performance While Maintaining Quality
- The Best WordPress Caching Plugins to Accelerate Your Website
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