Autoprefixer vs PurifyCSS: What are the differences?

# Introduction

Autoprefixer and PurifyCSS are popular tools used in web development to improve and optimize CSS files. Both tools have distinct differences that make them suitable for various scenarios.

1. **Browser Compatibility**: Autoprefixer automatically adds vendor prefixes to CSS properties based on current browser usage statistics, ensuring cross-browser compatibility. In contrast, PurifyCSS removes unused CSS rules from your stylesheets, reducing file size and improving loading times.
2. **Functionality**: Autoprefixer focuses on adding necessary prefixes to CSS properties, while PurifyCSS is used to eliminate unused CSS rules, reducing file size without altering the visual appearance of the website.
3. **Usage**: Autoprefixer is typically used in the build process of a project to ensure browser compatibility, while PurifyCSS is often employed during the optimization phase to remove unused styles and streamline the CSS files.
4. **Scope**: Autoprefixer primarily targets vendor prefixes for CSS properties, while PurifyCSS scans HTML files to identify and remove CSS rules that are not being utilized, providing a more tailored approach to optimizing stylesheets.
5. **Performance Impact**: Autoprefixer has minimal impact on performance, as it primarily adds necessary prefixes, while PurifyCSS can significantly reduce file size and improve page loading times by removing unused CSS, making it a valuable tool for performance optimization strategies.
6. **Output**: The output of Autoprefixer will have vendor prefixes added to CSS properties, ensuring cross-browser compatibility, while PurifyCSS output will have unused CSS rules removed, resulting in a more streamlined and efficient stylesheet.

In Summary, Autoprefixer focuses on ensuring cross-browser compatibility by adding vendor prefixes, while PurifyCSS eliminates unused CSS rules to optimize file size and improve loading times in web development projects.