CSS - align-items

Syntax  

/* Align to cross-start */
align-items: flex-start;

/* Align to cross-end */
align-items: flex-end;

/* Center items in the cross-axis */
align-items: center;

/* Align the items' baselines */
align-items: baseline;

/* Stretch the items to fit */
align-items: stretch;

/* Global values */
align-items: inherit;
align-items: initial;
align-items: unset;

Values

flex-start

The cross-start margin edge of the flex item is flushed with the cross-start edge of the line.

flex-end

The cross-end margin edge of the flex item is flushed with the cross-end edge of the line.

center

The flex item's margin box is centered within the line on the cross-axis. If the cross-size of the item is larger than the flex container, it will overflow equally in both directions.

baseline

All flex items are aligned such that their baselines align. The item with the largest distance between its cross-start margin edge and its baseline is flushed with the cross-start edge of the line.

stretch

Flex items are stretched such as the cross-size of the item's margin box is the same as the line while respecting width and height constraints.

Formal syntax

flex-start <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> flex-end <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> center <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> baseline <a title="Single bar" href="css/value_definition_syntax#single_bar">|</a> stretch

Description  

The CSS align-items property aligns flex items of the current flex line the same way as justify-content but in the perpendicular direction.

See Using CSS flexible boxes for more properties and information.

Browser Compatibility  

[1] Older versions of the spec treat absolute positioned children as though they are a 0 by 0 flex item. Later spec versions take them out of the flow and set their positions based on align and justify properties. Chrome implements the new behavior beginning with Chrome 52.

[2] To activate flexbox support in Firefox 18 and 19, the user has to visit about:config and change the value of the layout.css.flexbox.enabled preference to true. Multi-line flexbox has been supported since Firefox 28.

In addition to the unprefixed support, Gecko 48.0 (Firefox 48.0 / Thunderbird 48.0 / SeaMonkey 2.45) added support for a -webkit prefixed version of the property for web compatibility reasons behind the preference layout.css.prefixes.webkit, defaulting to false. Since Gecko 49.0 (Firefox 49.0 / Thunderbird 49.0 / SeaMonkey 2.46) the preference defaults to true.

[3] In Internet Explorer 10-11 (but not 12+), if column flex items have align-items: center; set on them and their content is too large, they will overflow the bounds of their container. See Flexbug #2 for more info.

See Also  

• Using CSS flexible boxes

Specifications  

License