Before

Pseudo-element

::before

Inserts generated content before the element's actual content. Requires the content property.

Example

.required::before {
  content: '*';
  color: red;
  margin-right: 4px;
}
.quote::before {
  content: open-quote;
}

Specificity

0-0-1

Browser Support

All browsers

About the Before

The ::before CSS selector belongs to the Pseudo-element category.Inserts generated content before the element's actual content. Requires the content property. Understanding CSS selector specificity and combinators is essential for writing maintainable stylesheets that behave predictably.

The specificity of this selector is 0-0-1. CSS specificity determines which styles are applied when multiple rules target the same element. Higher specificity values take precedence. The specificity hierarchy from lowest to highest is: universal (*) → type/element → class/attribute/pseudo-class → ID → inline styles → !important.

Browser support for Before is: All browsers. When using newer CSS selectors like :has(), :is(), or CSS nesting, consider providing fallback styles for older browsers. Use @supports to progressively enhance your stylesheets with modern features while maintaining backward compatibility.

Related Selectors

::after ::first-line ::first-letter