ID selectors

The CSS ID selector matches an element based on the value of the element’s id attribute. In order for the element to be selected, its id attribute must match exactly the value given in the selector.

/* The element with id="demo" */
#demo {
  border: red 2px solid;
}

Syntax

#id_value { style properties }

Note that syntactically (but not specificity-wise), this is equivalent to the following attribute selector:

[id=id_value] { style properties }

Example

CSS

#identified {
  background-color: skyblue;
}

HTML

<div id="identified">This div has a special ID on it!</div>
<div>This is just a regular div.</div>

Result

Specifications

Specification Status Comment
Selectors Level 4
The definition of 'ID selectors' in that specification.
Working Draft
Selectors Level 3
The definition of 'ID selectors' in that specification.
Recommendation
CSS Level 2 (Revision 1)
The definition of 'ID selectors' in that specification.
Recommendation
CSS Level 1
The definition of 'ID selectors' in that specification.
Recommendation Initial definition

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
ID selector (#idName)Chrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 3Opera Full support 3.5Safari Full support 1WebView Android Full support ≤37Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support 10.1Safari iOS Full support 1Samsung Internet Android Full support 1.0

Legend

Full support  
Full support