:checked - CSS: Cascading Style Sheets 编辑

The :checked CSS pseudo-class selector represents any radio (<input type="radio">), checkbox (<input type="checkbox">), or option (<option> in a <select>) element that is checked or toggled to an on state.

/* Matches any checked/selected radio, checkbox, or option */
:checked {
  margin-left: 25px;
  border: 1px solid blue;
}

The user can engage this state by checking/selecting an element, or disengage it by unchecking/deselecting the element.

Note: Because browsers often treat <option>s as replaced elements, the extent to which they can be styled with the :checked pseudo-class varies from browser to browser.

Syntax

:checked

Examples

Basic example

HTML

<div>
  <input type="radio" name="my-input" id="yes">
  <label for="yes">Yes</label>

  <input type="radio" name="my-input" id="no">
  <label for="no">No</label>
</div>

<div>
  <input type="checkbox" name="my-checkbox" id="opt-in">
  <label for="opt-in">Check me!</label>
</div>

<select name="my-select" id="fruit">
  <option value="opt1">Apples</option>
  <option value="opt2">Grapes</option>
  <option value="opt3">Pears</option>
</select>

CSS

div,
select {
  margin: 8px;
}

/* Labels for checked inputs */
input:checked + label {
  color: red;
}

/* Radio element, when checked */
input[type="radio"]:checked {
  box-shadow: 0 0 0 3px orange;
}

/* Checkbox element, when checked */
input[type="checkbox"]:checked {
  box-shadow: 0 0 0 3px hotpink;
}

/* Option elements, when selected */
option:checked {
  box-shadow: 0 0 0 3px lime;
  color: red;
}

Result

Toggling elements with a hidden checkbox

This example utilizes the :checked pseudo-class to let the user toggle content based on the state of a checkbox, all without using JavaScript.

HTML

<input type="checkbox" id="expand-toggle" />

<table>
  <thead>
    <tr><th>Column #1</th><th>Column #2</th><th>Column #3</th></tr>
  </thead>
  <tbody>
    <tr class="expandable"><td>[more text]</td><td>[more text]</td><td>[more text]</td></tr>
    <tr><td>[cell text]</td><td>[cell text]</td><td>[cell text]</td></tr>
    <tr><td>[cell text]</td><td>[cell text]</td><td>[cell text]</td></tr>
    <tr class="expandable"><td>[more text]</td><td>[more text]</td><td>[more text]</td></tr>
    <tr class="expandable"><td>[more text]</td><td>[more text]</td><td>[more text]</td></tr>
  </tbody>
</table>

<label for="expand-toggle" id="expand-btn">Toggle hidden rows</label>

CSS

/* Hide the toggle checkbox */
#expand-toggle {
  display: none;
}

/* Hide expandable content by default */
.expandable {
  visibility: collapse;
  background: #ddd;
}

/* Style the button */
#expand-btn {
  display: inline-block;
  margin-top: 12px;
  padding: 5px 11px;
  background-color: #ff7;
  border: 1px solid;
  border-radius: 3px;
}

/* Show hidden content when the checkbox is checked */
#expand-toggle:checked ~ * .expandable {
  visibility: visible;
}

/* Style the button when the checkbox is checked */
#expand-toggle:checked ~ #expand-btn {
  background-color: #ccc;
}

Result

Image gallery

You can use the :checked pseudo-class to build an image gallery with full-size images that show only when the user clicks on a thumbnail. See this demo for a possible cue.

Note: For an analogous effect, but based on the :hover pseudo-class and without hidden radioboxes, see this demo, taken from the :hover reference page.

Specifications

Specification	Status	Comment
HTML Living Standard The definition of ':checked' in that specification.	Living Standard	No change.
HTML5 The definition of ':checked' in that specification.	Recommendation	Defines the semantic regarding HTML.
Selectors Level 4 The definition of ':checked' in that specification.	Working Draft	No change.
Selectors Level 3 The definition of ':checked' in that specification.	Recommendation	Defines the pseudo-class, but not the associated semantic

BCD tables only load in the browser

• Web forms — working with user data
• Styling web forms
• Related HTML elements: <input type="checkbox">, <input type="radio">, <select>, and <option>
• Replaced elements