flex value

The <flex> CSS data type denotes a flexible length within a grid container. It is used in grid-template-columns, grid-template-rows and other related properties.


The <flex> data type is specified as a <number> followed by the unit fr. As with all CSS dimensions, there is no space between the unit and the number.


1fr    /* Using an integer value */
2.5fr  /* Using a float value */


Specification Status Comment
CSS Grid Layout
The definition of '<flex>' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support No support[1] 20 (12.10240) No support[2] 10.0 No support[1] Nightly build
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support[2] 10.0 No support No support

[1] Implemented behind the experimental Web Platform features flag in chrome://flags since Chrome 29.0 and Opera 28.0.

[2] Implemented behind the preference layout.css.grid.enabled, defaulting to false.

See also

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