`:-moz-only-whitespace` CSS pseudo-class

Non-standard: This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

Note: In Selectors Level 4, the :empty selector was changed to act like :-moz-only-whitespace, but no browser currently supports this yet.

The :-moz-only-whitespace CSS pseudo-class matches elements that only contain text nodes that only contain whitespace. (This includes elements with empty text nodes and elements with no child nodes.)

Syntax

:-moz-only-whitespace {
  /* ... */
}

Examples

Basic :-moz-only-whitespace example

HTML

<div> </div>

CSS

div {
  border: 4px solid red;
}

:-moz-only-whitespace {
  border-color: lime;
}

Result

Specifications

Briefly defined as :blank in Selectors Level 4, but then the functionality was merged into :empty and :blank redefined to mean empty <input>.

Browser compatibility

	Desktop					Mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`-moz-only-whitespace`	No	No	1	No	No	No	4	No	No	No	No	No