This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The <dimension> CSS data type represents a <number> with a unit attached to it, for example 10px.
CSS uses dimensions to specify distances (<length>), durations (<time>), frequencies (<frequency>), resolutions (<resolution>), and other quantities.
The syntax of <dimension> is a <number> immediately followed by a unit which is an identifier. Unit identifiers are case insensitive.
12px 12 pixels 1rem 1 rem 1.2pt 1.2 points 2200ms 2200 milliseconds 5s 5 seconds 200hz 200 Hertz 200Hz 200 Hertz (values are case insensitive)
12 px The unit must come immediately after the number. 12"px" Units are identifiers and therefore unquoted. 3sec The seconds unit is abbreviated "s" not "sec".
| Specification |
|---|
| CSS Values and Units Module Level 4> # dimensions> |
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | WebView on iOS | |
dimension |
1 | 12 | 1 | 3.5 | 1 | 18 | 4 | 10.1 | 1 | 1.0 | 4.4 | 1 |
<length>), durations (<time>), frequencies (<frequency>), and resolutions (<resolution>)
© 2005–2025 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/CSS/dimension