The flex-grow CSS property specifies the flex grow factor of a flex item. It specifies what amount of space inside the flex container the item should take up.

See Using CSS flexible boxes for more properties and information.


flex-grow: 3;

/* Global values */
flex-grow: inherit;
flex-grow: initial;
flex-grow: unset;


See <number>. Negative values are invalid.

Formal syntax



element { 
  flex-grow: 3;


Specification Status Comment
CSS Flexible Box Layout Module
The definition of 'flex-grow' in that specification.
Last Call Working Draft  

Browser compatibility

Feature Firefox (Gecko) Chrome Internet Explorer Opera Safari
Basic support 18.0 (18.0) [1]
20.0 (20.0) [2]


11 12.10 6.1-webkit
Feature Firefox Mobile (Gecko) Android IE Phone Opera Mobile Safari Mobile
Basic support 18.0 (18.0) [1]
20.0 (20.0) [2]
? Not supported 12.10 Not supported

[1] Firefox supports only single-line flexbox until Firefox 28. To activate flexbox support, for Firefox 18 and 19, the user has to change the about:config preference "layout.css.flexbox.enabled" to true.

[2] Before Firefox 32, Gecko wasn't able to animate values starting or stopping at 0.

See also

Document Tags and Contributors

Last updated by: meznaric,