Should You Avoid the CSS Star Selector for Better Performance and Maintainability?

Should You Use the CSS Star Selector with Caution?

The CSS star selector (*) is a wildcard selector that matches all elements in a document. While it may seem convenient to use, there are concerns about its impact on performance and potential limitations.

Performance Impact

According to performance expert Steve Souders, the star selector can negatively affect page rendering time. Browsers process CSS selectors right-to-left, starting with the key selector (the rightmost one). In the example below, the key selector is "*":

* {
  margin: 0;
  padding: 0;
}

This means the browser has to check every element in the document to apply the styles, which can be computationally expensive.

Other Concerns

Besides performance, there are other caveats to using the star selector:

• Overly Broad: It can target more elements than intended, leading to unexpected styling effects.
• Specificity Issues: It has a specificity of 0, which can be overridden by more specific selectors.
• Code Reusability: It can make code less reusable as it applies styles globally.

When to Use the Star Selector

Despite its limitations, the star selector can be useful in certain scenarios:

• Resetting Styles: It can be used to reset browser default styles on all elements.
• Global Modifications: It can be used to make global changes to the appearance of the entire page.

Conclusion

While the CSS star selector can be convenient, it's important to use it sparingly due to its potential performance impact and other limitations. Understanding its behavior and using alternatives when appropriate can help maintain optimal page rendering performance and code maintainability.

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