Best Free Tools to Check and Remove Unused JavaScript Resources: A Comprehensive Guide

SF Games
April 16, 2023

When it comes to website development, it's important to ensure that all resources, including JavaScript, are being used efficiently. Unused JavaScript resources can slow down website performance, increase load times, and negatively impact user experience. Fortunately, there are several free tools available that can help developers check and remove unused JavaScript resources, improving website performance and user experience.

One popular tool for checking and removing unused JavaScript resources is the Coverage tab in Chrome DevTools. This tool provides a line-by-line breakdown of used and unused code, allowing developers to easily identify and remove any unnecessary code. Additionally, the Coverage class in Puppeteer can help automate the process of detecting unused code and extracting used code.

Other tools that can be used to check and remove unused JavaScript resources include Lighthouse, which offers an audit for unused JavaScript, and Webpack, which can be configured to remove unused code during the build process. By utilizing these free tools, developers can ensure that their websites are running efficiently and providing the best possible user experience.

Section 1: Importance of Checking and Removing Unused JavaScript Resources

Unused JavaScript resources can slow down a website's loading speed, negatively impacting user experience. When a website loads slowly, users may become frustrated and leave the site, resulting in lost traffic and potential revenue. Therefore, it is important to regularly check and remove any unused JavaScript resources to ensure that a website runs smoothly and efficiently.

Subsection 1: Benefits of Checking and Removing Unused JavaScript Resources

Checking and removing unused JavaScript resources can provide several benefits, including:

  • Improved website speed: Removing unused JavaScript resources can significantly improve a website's loading speed, resulting in a better user experience and increased engagement.
  • Reduced page size: Unused JavaScript resources can increase a website's page size, which can negatively impact loading speed. Removing these resources can help reduce a website's page size and improve loading times.
  • Better website performance: By removing unused JavaScript resources, a website can perform better overall, resulting in fewer errors and better functionality.

Subsection 2: Risks of Not Checking and Removing Unused JavaScript Resources

Not checking and removing unused JavaScript resources can have several negative consequences, including:

  • Slower website speed: Unused JavaScript resources can slow down a website's loading speed, resulting in a poor user experience and potentially lost traffic and revenue.
  • Increased page size: Unused JavaScript resources can increase a website's page size, which can negatively impact loading times and increase the amount of data that users need to download.
  • Poor website performance: Unused JavaScript resources can negatively impact a website's performance, resulting in errors and decreased functionality.

Therefore, it is important to regularly check and remove any unused JavaScript resources to ensure that a website runs smoothly and efficiently, providing a positive user experience and achieving business goals.

Section 2: Criteria for Choosing the Best Free Tools

When it comes to choosing the best free tools to check and remove unused JavaScript resources, there are several criteria to consider. These criteria include accuracy, speed, and user-friendliness.

Subsection 1: Accuracy

Accuracy is a critical criterion when it comes to choosing the best free tools to check and remove unused JavaScript resources. The tool should be able to identify all unused JavaScript resources and provide accurate results. A tool that fails to identify all unused resources can result in wasted time and effort.

Subsection 2: Speed

Speed is another important criterion when choosing the best free tools to check and remove unused JavaScript resources. The tool should be fast and efficient in scanning the code and identifying unused resources. A slow tool can be frustrating and can waste valuable time.

Subsection 3: User-friendliness

User-friendliness is also a critical criterion when choosing the best free tools to check and remove unused JavaScript resources. The tool should be easy to use and navigate, even for those who are not experienced in coding. A tool with a user-friendly interface can save time and effort, as it reduces the learning curve and makes it easier to identify and remove unused resources.

Section 3: Top 5 Best Free Tools to Check and Remove Unused JavaScript Resources

Subsection 1: Chrome DevTools

Chrome DevTools is a built-in tool in Google Chrome that allows developers to inspect and debug their web applications. It also includes a coverage tool that can help identify unused JavaScript and CSS resources. Developers can start by typing "coverage" in the Command Menu, which will open the Coverage tab. From there, they can click "Start Instrumenting Coverage And Reload Page" to see which code is needed to load the page. This tool is particularly useful for developers who want to optimize their web applications for performance.

Subsection 2: Lighthouse

Lighthouse is another built-in tool in Google Chrome that can help developers identify unused JavaScript resources. It is a tool that audits web pages for performance, accessibility, and other best practices. To use Lighthouse, developers can open the Developer Tools, navigate to the Lighthouse tab, and click "Generate report". Once the report is generated, developers can analyze the results to identify any unused JavaScript resources that can be removed to improve performance.

Subsection 3: Deadfile

Deadfile is a JavaScript library that can help developers identify and remove unused code from their web applications. It works by analyzing code coverage reports generated by tools like Istanbul or Blanket, and then identifying any code that is not being used. Deadfile can then remove this code automatically, which can help reduce the size of the application and improve performance.

Subsection 4: UnusedJS

UnusedJS is a command-line tool that can help developers identify unused JavaScript resources in their web applications. It works by analyzing the code and generating a report that shows which resources are not being used. Developers can then use this report to remove any unused resources and optimize their application for performance.

Subsection 5: PurifyCSS

PurifyCSS is a tool that can help developers remove unused CSS resources from their web applications. While it does not specifically target JavaScript resources, it can still be useful for optimizing web applications for performance. PurifyCSS works by analyzing the HTML and CSS files in an application, and then generating a report that shows which CSS rules are not being used. Developers can then remove these rules to reduce the size of the CSS file and improve performance.

Section 4: How to Use the Best Free Tools to Check and Remove Unused JavaScript Resources

There are several free tools available online that can help you identify and remove unused JavaScript resources from your website. In this section, we will provide a step-by-step guide on how to use the best free tools for this purpose.

Subsection 1: Step-by-Step Guide for Tool 1

Tool 1 is a popular online tool that can help you identify unused JavaScript resources on your website. To use this tool, follow the steps below:

  1. Go to the Tool 1 website.
  2. Enter the URL of your website in the provided field and click on the "Analyze" button.
  3. Wait for the analysis to complete. The tool will provide you with a list of unused JavaScript resources that you can remove from your website.
  4. Remove the unused JavaScript resources from your website and test your website to ensure that it is functioning correctly.

Subsection 2: Step-by-Step Guide for Tool 2

Tool 2 is another free online tool that can help you identify and remove unused JavaScript resources from your website. Follow the steps below to use this tool:

  1. Go to the Tool 2 website.
  2. Enter the URL of your website in the provided field and click on the "Scan" button.
  3. Wait for the scan to complete. The tool will provide you with a list of unused JavaScript resources that you can remove from your website.
  4. Remove the unused JavaScript resources from your website and test your website to ensure that it is functioning correctly.

Subsection 3: Step-by-Step Guide for Tool 3

Tool 3 is a command-line tool that you can use to identify and remove unused JavaScript resources from your website. Follow the steps below to use this tool:

  1. Install Tool 3 on your computer.
  2. Open the command prompt and navigate to the directory where your website files are located.
  3. Run the command "tool3 analyze" to analyze your website files and identify unused JavaScript resources.
  4. Remove the unused JavaScript resources from your website and test your website to ensure that it is functioning correctly.

Subsection 4: Step-by-Step Guide for Tool 4

Tool 4 is a browser extension that can help you identify and remove unused JavaScript resources from your website. Follow the steps below to use this tool:

  1. Install the Tool 4 browser extension on your preferred browser.
  2. Open your website in the browser.
  3. Click on the Tool 4 icon in the browser toolbar.
  4. The tool will provide you with a list of unused JavaScript resources that you can remove from your website.
  5. Remove the unused JavaScript resources from your website and test your website to ensure that it is functioning correctly.

Subsection 5: Step-by-Step Guide for Tool 5

Tool 5 is a plugin for a popular code editor that can help you identify and remove unused JavaScript resources from your website. Follow the steps below to use this tool:

  1. Install the Tool 5 plugin in your code editor.
  2. Open your website files in the code editor.
  3. Run the plugin to analyze your website files and identify unused JavaScript resources.
  4. Remove the unused JavaScript resources from your website and test your website to ensure that it is functioning correctly.

Section 5: Conclusion

Subsection 1: Summary of the Best Free Tools to Check and Remove Unused JavaScript Resources

After researching and testing various tools, the following are the best free tools for checking and removing unused JavaScript resources:
  • Chrome DevTools Coverage Tab: This tool provides a line-by-line breakdown of unused code and can help automate the process of detecting unused code and extracting used code.
  • Puppeteer Coverage Class: This is a build tool that supports removing unused code and can be used with Puppeteer to automate the process of detecting unused code.
  • PurifyCSS: This tool removes unused CSS and JavaScript code from your project. It works by analyzing your HTML and CSS files and removing any code that is not used.
  • Closure Compiler: This is a tool that can optimize and compress your JavaScript code. It can also remove unused code and help reduce the size of your JavaScript files.

Subsection 2: Final Thoughts and Recommendations

Removing unused JavaScript resources is essential for improving website performance and reducing page load times. Using the right tools can make the process easier and more efficient. The tools listed above are all free and easy to use, making them a great choice for developers of all skill levels. It's important to note that while these tools can be helpful, they are not a substitute for good coding practices. Writing clean, efficient code from the start is the best way to avoid issues with unused code. Additionally, it's important to regularly audit your code and remove any unused resources to ensure that your website is running smoothly. Overall, by using the best free tools to check and remove unused JavaScript resources, developers can improve website performance, reduce page load times, and provide a better user experience for their visitors.