1. Brief Description of CSS Minifier

CSS minifier is a software tool that decreases Cascading Style Sheets (CSS) file size by removing unnecessary characters, such as whitespace, comments, and redundant code. This is done without affecting CSS functionality. It aims to improve website performance by reducing CSS download and parsing time. By optimizing CSS code, a minifier minimizes bandwidth usage and improves web page loading speed.

2. Five Key Features of CSS Minifier

Removal of whitespace and comments.
One of the primary features of a CSS minifier is the removal of whitespace and comments from CSS files. Whitespace and comments are essential for code readability during development but not for CSS execution in a web browser. A CSS minifier significantly reduces file size by eliminating unnecessary elements.

Compression of CSS Code

CSS minifiers employ various compression techniques to reduce CSS file size further. These techniques include shortening property names, abbreviating color codes, and using shorthand notations where applicable. Compression ensures that CSS code is highly optimized and consumes minimal resources.

Optimization of selectors and properties

CSS minifiers go beyond whitespace removal and compression. It also optimizes selectors and properties to enhance CSS efficiency. This optimization includes removing redundant selectors, merging duplicate properties, and reordering rules to minimize redundancy and improve performance.

Preservation of functionality

While CSS minification is designed to reduce file size, it is crucial to preserve the functionality of CSS. A reliable minifier ensures that the optimized CSS code behaves identically to the original code without unintended side effects. This 
Includes handling complex CSS features, such as media queries, pseudo-classes, and animations, to maintain the intended behavior of the styles.

Support for batch processing

To streamline the optimization process, many CSS minifiers offer batch processing capabilities. Batch processing allows you to minify multiple CSS files simultaneously, saving time and effort. Batch processing is particularly useful when working on large projects with multiple CSS files or integrating a minification step into a build process.