3 Best Plugins to Remove Unused CSS from Your WordPress Website and Improve PageSpeed.

Reduce unused CSS (previously remove unused CSS) is one of the most challenging suggestions triggered by Google pagespeed insights when you are auditing your website’s pagespeed performance

What is unused CSS? And how to remove this?

Unused CSS code is any CSS style or rules that you don’t need. Removing this unused CSS rule can improve your website’s page speed performance for a better conversion rate as well as better SEO rankings. 

how to remove unused css

Don’t worry! If you are not from a technical background. Here we will discuss the strategies that will help non-coders like you and thousands of other wordpress website owners to remove unused CSS.  

What is Unused CSS

Unused CSS refers to the stylesheets or style rules that are present in your website’s codebase but not applied to any elements on the webpage.

remove unused css

Unused CSS can occur due to several reasons such as design changes, code updates, or unused stylesheets from the CSS framework or library. This unused CSS makes the file larger than necessary and increases the loading time of your website. 

Type of Unused CSS:

Unused CSS generally falls into two categories. Both categories will affect your pagespeed performance in different ways.

  • Non-Critical CSS:

Non-critical CSS is also known as deferred CSS. It refers to a stylesheet that is not necessary for rendering the visible area or above the fold.

non critical css
  • Dead CSS :

Dead CSS refers to the CSS stylesheets that are no longer applied or used to elements on a website. They are basically remnants from the previous version of your website or maybe a part of testing or temporary usage.

Why Should You Remove Unused CSS File

Unused CSS stylesheets that are not needed to render a page, can be as files or as internal styles for the page contents on a web page. These unused CSS files can have several performance impacts on your website, affecting page loading time as well as user experience. 

  • Unused CSS Increases Page Loading Time:

An unused CSS makes a file larger, which will increase the web page loading time for a user. This is especially critical for the user who is using a slower network connection.

Increase Page Loading Times

Larger CSS files increase the network overhead browser needs to download more data. This can be problematic for your website to attract high traffic.  

  • Unused CSS Impacts on LCP Negatively:

Non-critical CSS also affects the core web vitals, especially on Largest Contentful Paint (LCP), making it lengthier which drags your pagespeed score down.

csimpacts on lcp

LCP is a user experience (UX) metric that indicates the time length taken to load a large content such as images, text blocks, etc. To provide a better user experience it should be less than 2.5 seconds.

  • Delayed Browser Rendering:

When a user visits any website, the browser will download, parse, and process the content of the website before displaying or rendering the webpage content. Hence, whether used or not, the browser will download each CSS file from the server.

Browser rendering process

A delayed render ,means user experience would be far from optimal.

  • Mobile Performance Issue:

Mobile users often have limited resources compared to desktop users. The desktop has a better internet speed than the mobile. It has a better processor and it can be connected to the Internet with the help of cables.

mobile performance issue, remove unused css

Whereas the mobile uses the data network and wireless connections. So, they may experience more issues when downloading and rendering large CSS files.

Check out: Core Web Vitals

How to Remove Unused CSS Manually

Removing the unused CSS file manually is a meticulous process and a piece of coding knowledge is required for this. Here we are mentioning some strategies that you can follow.

  1. Audit Your Code to Remove Unused CSS:

You need to go through the whole HTML file and identify which CSS classes and IDs are not being used. It can be done by searching for a specific class or ID in your HTML code.

audit unused css

This process is very time-consuming. You can also use any browser developer tool such as Chrome DevTool or Firefox Developer Edition. These tools allow you to identify unused CSS rules. The CSS that is solid red indicates the code is unused.

  1. Remove Unused CSS Styles:

Once you have identified the unused CSS codes, remove these codes from your style sheet. Be very careful, not to delete the CSS rule that may be used conditionally.

Style code unused
  1. Test Your Changes:

After removing all unused CSS rules from your stylesheets, you need to test your website once to ensure that no visual or functional issue has arisen.

Tools to Remove Unused CSS 

There are several online tools available to remove unused CSS files to improve web performance. These tools can help you to analyze your CSS stylesheets and extract only the used CSS rules. Here is an overview of the popular tools.

1. PurifyCSS:

PurifyCSS is a free online tool that helps to remove unused CSS from your HTML, JS file, and CSS files. But you need to manually specify which files need to be scanned one by one.

Purify css online,remove unused css

PurifyCSS provides new files with optimized CSS rather than modifying the original files. Since it doesn’t work with any live website, you need to use it in development settings.  

2. UnusedCSS:

UnusedCSS is a user-friendly online tool for removing unused CSS. you just need to plug the website’s URL into UnusedCSS. It will identify and remove unused CSS code and also tell you how much memory you have saved.

unused css

You can try this tool for free but you need to pay for a monthly membership to download the optimized files. 

3. PurgeCSS:

PurgeCSS looks very similar to PurifyCSS which helps you to analyze your webpage content and your CSS files. It removes the unused CSS selector from your CSS and provides a smaller file.  

Purge css

Best Plugins to Remove Unused CSS for WordPress Websites.

The easiest way to remove unused CSS is to use one of the WordPress optimization plugins that can help you remove unused CSS. There are many optimization plugins available that can help you. Here we are mentioning a few popular WordPress plugins.

1. RabbitLoader:

RabbitLoader is an all-in-one performance optimization plugin that you can use to remove unused CSS features. Apart from this RabbitLoader uses various techniques like code optimization, image optimization, a premium CDN, and many more to speed up your website. 

rabbitloader,remove unused css

When you are using RabbitLoader no other plugin is required. The advantage of RabbitLoader over the other optimization tools is the availability of a free version.

2. WP Rocket:

WP Rocket is the most popular WordPress plugin that optimizes your website. It uses various optimization techniques like minification of CSS files and unused JavaScript files, caching, and others. 

WP rocket

But when you are using WP Rocket in your WordPress site you need to install Imagify for image optimization, a premium CDN that is known as RocketCDN, and for lazy loading, you need Rocket lazy loading. It is only available in the WordPress ecosystem.

3. Asset Cleanup:

Asset cleanup is a plugin that helps you to reduce unused CSS to improve the WordPress website’s pagespeed. First, it will fetch the homepage and will show you all CSS files loaded on that page.

asets cleanup, remove unused css

You need to review all loaded files. If you find any files that you don’t need then you need to unload that file.


We hope this article will help you to understand Unused CSS and guide you to remove unused CSS. If you are comfortable with coding then you can remove unused CSS manually. But if you are not a coder like me then you can install any optimization tools that can help you to reduce unused CSS.

If you are a beginner, We suggest you install the all-in-one performance optimization tool RabbitLoader which can help you to optimize your website pagespeed. It will improve the user experience as well as the conversion rate.