Specificity Hierarchy
Each type of CSS selector has a position in the specificity hierarchy, and the selector types carry different "weights".
| Selector | Example | Description | Weight |
|---|---|---|---|
| Inline styles | Highest priority, will override all other selectors | ||
| Id selectors | #navbar | Second highest priority | 1-0-0 |
| Classes, attribute selectors and pseudo-classes | .test, [type="text"], :hover | Third highest priority | 0-1-0 |
| Elements and pseudo-elements | h1, ::before, ::after | Low priority | 0-0-1 |
| Universal selector and :where() | *, where() | No priority | 0-0-0 |
Understand the Weight Notation
The weight notation uses three numbers (X-Y-Z):
- X - Number of ID selectors
- Y - Number of class selectors, attribute selectors, and pseudo-classes
- Z - Number of element selectors and pseudo-elements
The selector with the higher leftmost number wins. If equal, compare the next number, and so on.
Calculate the Specificity Weight
The declaration with the highest specificity/weight value will be applied to the element.
Example
<html>
<head>
<style>
#demo {color: blue;} /* weight: 1-0-0 */
p#demo {color:
orange;} /* weight: 1-0-1 WINS! */
.test {color: green;}
/* weight: 0-1-0 */
p.test {color: green;} /* weight:
0-1-1 */
p {color: red;} /* weight: 0-0-1 */
</style>
</head>
<body>
<p id="demo" class="test">Hello World!</p>
</body>
</html>
More Specificity Examples
Understand how specificity works in different scenarios:
Equal specificity: the latest rule wins
If the same rule is written twice in the external style sheet, the latest rule wins:
Example
h1 {background-color: yellow;}
h1 {background-color: red;}
ID selectors beat attribute selectors
Look at the following code lines - Here, the first rule has higher specificity than the second, and will therefore be applied:
Example
#myDiv {background-color: yellow;}
div[id=myDiv] {background-color: blue;}
A class selector beats element selectors
A class selector such as .intro beats h1, p, div, etc:
Example
.intro {background-color: yellow;}
h1 {background-color:
red;}
The universal selector (*)
The universal selector (*) has no specificity weight value:
Example
* {background-color: yellow;}
h1 {background-color: red;}
Inline style vs external style sheet
The embedded style sheet is closer to the element to be styled. So in the following situation the last rule will be applied:
Example
/*From external CSS file:*/
#content h1 {background-color: red;}
/*In HTML file:*/
<style>
#content h1 {background-color:
yellow;}
</style>
