The :only-child CSS pseudo-class represents an element without any siblings. This is the same as :first-child:last-child or :nth-child(1):nth-last-child(1), but with a lower specificity.
/* Selects each <p>, but only if it is the */
/* only child of its parent */
p:only-child {
background-color: lime;
} Note: As originally defined, the selected element had to have a parent. Beginning with Selectors Level 4, this is no longer required.
:only-child
<div> <div>I am an only child.</div> </div> <div> <div>I am the 1st sibling.</div> <div>I am the 2nd sibling.</div> <div>I am the 3rd sibling, <div>but this is an only child.</div></div> </div>
div:only-child {
color: red;
}
div {
display: inline-block;
margin: 6px;
outline: 1px solid;
}
<ol>
<li>First
<ul>
<li>This list has just one element.
</ul>
</li>
<li>Second
<ul>
<li>This list has three elements.
<li>This list has three elements.
<li>This list has three elements.
</ul>
</li>
</ol>
li li {
list-style-type: disc;
}
li:only-child {
color: red;
list-style-type: square;
} | Specification | Status | Comment |
|---|---|---|
| Selectors Level 4 The definition of ':only-child' in that specification. | Working Draft | Matching elements are not required to have a parent. |
| Selectors Level 3 The definition of ':only-child' in that specification. | Recommendation | Initial definition. |
| Desktop | ||||||
|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
| Basic support | 2 | Yes | 1.5 | 9 | 9.5 | 3.1 |
| Matches elements with no parent | 57 | ? | 52 | ? | 44 | ? |
| Mobile | |||||||
|---|---|---|---|---|---|---|---|
| Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
| Basic support | Yes | Yes | Yes | 4 | 10 | 3.1 | Yes |
| Matches elements with no parent | 57 | 57 | ? | 52 | 44 | ? | 7.0 |
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/CSS/:only-child