CSS - grid-auto-columns

The grid-auto-columns CSS property specifies the size of an implicitly-created grid column track.

Example

 

HTML Content

HTML
<div id="grid">
  <div id="item1"></div>
  <div id="item2"></div>
  <div id="item3"></div>
</div>

CSS Content

CSS
#grid {
  height: 100px;
  display: grid;
  grid-template-areas: "a a";
  grid-gap: 10px;
  grid-auto-columns: 200px;
}

#grid > div {
  background-color: lime;
}

Syntax  

CSS
/* Keyword values */
grid-auto-columns: min-content;
grid-auto-columns: max-content;
grid-auto-columns: auto;

/* <length> values */
grid-auto-columns: 100px;
grid-auto-columns: 20cm;
grid-auto-columns: 50vmax;

/* <percentage> values */
grid-auto-columns: 10%;
grid-auto-columns: 33.3%;

/* <flex> values */
grid-auto-columns: 0.5fr;
grid-auto-columns: 3fr;

/* minmax() values */
grid-auto-columns: minmax(1fr, 300px);
grid-auto-columns: minmax(max-content, 2fr);
grid-auto-columns: minmax(20%, 80vmax);

/* Global values */
grid-auto-columns: inherit;
grid-auto-columns: initial;
grid-auto-columns: unset;

Values

<length>
Is a non-negative length.
<percentage>
Is a non-negative <percentage> value relative to the block size of the grid container. If the block size of the grid container is indefinite, the percentage value is treated like auto.
<flex>
Is a non-negative dimension with the unit fr specifying the track’s flex factor. Each <flex>-sized track takes a share of the remaining space in proportion to its flex factor.

When appearing outside a minmax() notation, it implies an automatic minimum (i.e. minmax(auto, <flex>)).

max-content
Is a keyword representing the largest maximal content contribution of the grid items occupying the grid track.
min-content
Is a keyword representing the largest minimal content contribution of the grid items occupying the grid track.
minmax(min, max)
Is a functional notation that defines a size range greater than or equal to min and less than or equal to max. If max is smaller than min, then max is ignored and the function is treated as min. As a maximum, a <flex> value sets the track’s flex factor. As a minimum, it is treated as zero (or minimal content, if the grid container is sized under a minimal content constraint).
auto
Is a keyword that is identical to maximal content if it's a maximum. As a minimum it represents the largest minimum size (as specified by min-width/min-height) of the grid items occupying the grid track.

Note: auto track sizes (and only auto track sizes) can be streched by the align-content and justify-content properties.

Formal syntax

CSS
<a href="css/grid-auto-columns#track-size"><track-size></a><p>where <br><code><track-size> = <a href="css/grid-auto-columns#track-breadth"><track-breadth></a> <a href="css/value_definition_syntax#single_bar" title="Single bar">|</a> minmax( <a href="css/grid-auto-columns#track-breadth"><track-breadth></a> , <a href="css/grid-auto-columns#track-breadth"><track-breadth></a> )</code></p><p>where <br><code><track-breadth> = <a href="css/length" title="Possible values: a number followed by'em', 'ex', 'ch', 'rem', 'px', 'cm', 'mm', 'in', 'vh', 'vw', 'vmin', 'vmax', 'pt', 'pc' or 'px', like 3px, 1.5cm, -0.5em or 0"><length></a> <a href="css/value_definition_syntax#single_bar" title="Single bar">|</a> <a href="css/percentage" title=""><percentage></a> <a href="css/value_definition_syntax#single_bar" title="Single bar">|</a> <flex> <a href="css/value_definition_syntax#single_bar" title="Single bar">|</a> min-content <a href="css/value_definition_syntax#single_bar" title="Single bar">|</a> max-content <a href="css/value_definition_syntax#single_bar" title="Single bar">|</a> auto</code></p>

Description  

The grid-auto-columns CSS property specifies the size of an implicitly-created grid column track.

If a grid item is positioned into a column that is not explicitly sized by grid-template-columns, implicit grid tracks are created to hold it. This can happen either by explicitly positioning into a column that is out of range, or by the auto-placement algorithm creating additional columns.

Initial valueauto
Applies togrid containers
Inheritedno
Percentagessee grid-template-rows or grid-template-columns
Mediavisual
Computed valuesee grid-template-rows or grid-template-columns
Animatableno
Canonical orderthe unique non-ambiguous order defined by the formal grammar

Browser Compatibility  

Feature Chrome Firefox (Gecko) Internet Explorer Edge Opera Safari
Basic support 29.0[1] 40.0 (40.0)[2] 10.0-ms[3] 20-ms[3] 28.0[1] Nightly build-webkit
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support Not supported Not supported 10.0-ms[3] Not supported Not supported

[1] Implemented behind the experimental Web Platform features flag in chrome://flags.

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

[3] Internet Explorer implements an older version of the specification using the -ms prefix. Therefore the property is implemented there as -ms-grid-columns.

See Also  

Specifications  

Specification Status Comment
CSS Grid Layout
The definition of 'grid-auto-columns' in that specification.
Working Draft Initial definition

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/css/grid-auto-columns

CSS CSS Grid CSS Property Reference