CSS Optimization
Writing efficient CSS is crucial for website performance. Optimized CSS leads to faster rendering, better user experience, and easier maintenance.
Minify Your CSS
Minification is the process of removing all unnecessary characters from source code without changing its functionality. This includes removing whitespace, comments, and newlines. This results in smaller file sizes, which load faster.
Example
Unminified:
.my-class {
color: red; /* a comment */
}Minified:
.my-class{color:red}You can use our Code Minifier tool for this.
Reduce Complexity
Overly complex selectors can slow down browser rendering. Try to keep your selectors as simple and efficient as possible.
- Avoid overly qualified selectors: Instead of
div.my-class, just use.my-class. - Avoid deep nesting: In preprocessors like SASS, avoid nesting selectors too deeply as it can create very long, overly specific selectors.
- Use classes over tags: Class selectors (
.my-class) are more efficient for browsers to match than tag selectors (div).
Avoid @import
Using the @import rule inside your CSS files to include other stylesheets can block parallel downloading, slowing down your page. It's better to include all stylesheets with separate <link> tags in your HTML's <head>.
Good vs. Bad Practice
Good (in HTML):
<link rel="stylesheet" href="style1.css">
<link rel="stylesheet" href="style2.css">Bad (in CSS):
@import url("style2.css");Test Yourself with an Exercise
What is the process of removing unnecessary characters from a CSS file called?