The checked selector is used to select all checked elements in the input tag and radio buttons. This selector is used with radio buttons, checkbox and option elements.
Syntax:
:checked {
// CSS property
}
Example 1: In this example, The CSS :checked selector targets checked input elements. It sets a height and width for checked checkboxes and applies a green color to the h1 element.
html <!DOCTYPE html> <html> <head> <title> checked selector property </title> <style> h1 { color: green; } input:checked { height: 8px; width: 10px; } body { width: 60%; } </style> </head> <body> <h1>GeeksforGeeks</h1> <h2>:checked Selector</h2> <form action=""> Gender: <input type="radio" checked="checked" value="male" name="gender"> Male <input type="radio" value="female" name="gender"> Female<br><br> Computer Science Subjects:<br> <input type="checkbox" checked="checked" value="Bike"> Computer Network<br> <input type="checkbox" checked="checked" value="Bike"> Operating System<br> <input type="checkbox" value="Bike"> Mathematics<br> <input type="checkbox" value="Bike"> Physics<br> </form> </body> </html> Output: 
Example 2: In this example, The CSS option:checked selector targets the selected option within a <select> element. It sets a height of 10px and a font size of 20px for the selected option.
html <!DOCTYPE html> <html> <head> <title>checked selector</title> <style> option:checked { height: 10px; font-size: 20px; } h1 { color: green; } </style> </head> <body> <center> <h1>GeeksForGeeks</h1> <h2>:checked Selector in <option> Element</h2> <select> <option value="DataStructure"> Data Structure </option> <option value="Computer Network"> Computer Network </option> <option value="Operating System"> Operating System </option> <option value="Computer Architecture"> Computer Architecture </option> </select> </center> </body> </html> Output: 
Supported Browsers: The browser supported by :checked Selector are listed below:
- Apple Safari 3.1 and above
- Google Chrome 1.0 and above
- Edge 12.0 and above
- Firefox 1.0 and above
- Opera 9.0 and above