How To Tell What Css Isn’t Being Used

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Hey there! Today I am going to talk about a topic that every web developer can relate to – how to tell what CSS isn’t being used. As a web developer myself, I have struggled with this issue many times and I know how frustrating it can be when you have a bunch of unused CSS cluttering up your code. But fear not, because I am here to guide you through the process of identifying and removing those unused styles!

Why is it important to remove unused CSS?

Before we dive into the process, let’s take a moment to understand why it is important to remove unused CSS in the first place. There are a few reasons for this:

  1. Improving page load time: One of the key factors that affect a website’s performance is its page load time. Having unnecessary CSS files that are not being used adds unnecessary weight to your website, making it slower to load.
  2. Reducing file size: Removing unused CSS helps to reduce the overall file size of your stylesheets, making them easier to manage and maintain.
  3. Enhancing code readability: By removing unused CSS, you can make your code more readable and easier to understand for both yourself and other developers who may work on the project in the future.

Identifying unused CSS

Now that we understand the importance of removing unused CSS, let’s explore some techniques to identify which styles are not being used in your code:

1. Manual Review:

One of the simplest ways to identify unused CSS is by manually reviewing your code. This involves going through each CSS rule and determining if it is being applied to any element on your website. While this method can be time-consuming, it allows you to gain a deeper understanding of your codebase and potentially catch any other issues along the way.

2. Browser Developer Tools:

Another effective way to identify unused CSS is by using your browser’s built-in developer tools. Most modern browsers offer a “Coverage” or “Audits” tab in their developer tools that can help you identify unused styles. These tools analyze your code and provide a report highlighting the CSS that is not being used on your website.

To use this feature, simply open your browser’s developer tools, navigate to the “Coverage” or “Audits” tab, and run the analysis. The tool will generate a report showing which CSS rules are not being used. From there, you can remove the unused styles and optimize your code.

3. Automated Tools:

If manual review and browser developer tools are not sufficient for your needs, there are also several automated tools available that can help you identify and remove unused CSS. Some popular options include:

  • PurifyCSS: A tool that analyzes your HTML and JavaScript files to determine which CSS selectors are actually being used.
  • UnCSS: A tool that scans your HTML files and removes any unused CSS based on the selectors it finds.
  • CSS Stats: A tool that provides valuable insights and analysis of your CSS, including identifying unused styles.

Removing unused CSS

Once you have identified the unused CSS in your code, it’s time to remove it and optimize your stylesheets. Here are a few tips to help you with the removal process:

  • Backup your code: Before making any changes, it’s always a good idea to create a backup of your code. This ensures that you can revert back to the original state if anything goes wrong.
  • Organize your stylesheets: Take the opportunity to organize your stylesheets and remove any unnecessary or duplicate code. This will make your code more maintainable in the long run.
  • Test your changes: After removing unused CSS, thoroughly test your website to ensure that all styles are still applied correctly and that no unintended side effects have occurred.


Removing unused CSS is an essential step in optimizing your website’s performance and maintaining a clean and efficient codebase. By following the techniques and tools outlined in this article, you can identify and remove those unnecessary styles, resulting in faster load times, smaller file sizes, and improved code readability. So, let’s roll up our sleeves and start decluttering our CSS!