- Initial value
- Applies to flex containers
- Inherited no
- Computed value as specified
- Animatable no
- Canonical order the unique non-ambiguous order defined by the formal grammar
See Using CSS flexible boxes for more properties and information.
flex-start | flex-end | center | baseline | stretch
align-items: flex-start align-items: flex-end align-items: center align-items: baseline align-items: stretch align-items: inherit
- The cross-start margin edge of the flex item is flushed with the cross-start edge of the line.
- The cross-end margin edge of the flex item is flushed with the cross-end edge of the line.
- 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.
- 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.
- 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.
|CSS Flexible Box Layout Module||Candidate Recommendation|
|Feature||Chrome||Firefox (Gecko)||Internet Explorer||Opera||Safari|
|Basic support||21.0-webkit||18.0 (18.0) (behind a pref) 
|Feature||Android||Chrome for Android||Firefox Mobile (Gecko)||IE Mobile||Opera Mobile||Safari Mobile|
|Basic support||4.4||?||?||Not supported||12.10||7.0-webkit|
 To activate flexbox support, for Firefox 18 and 19, the user has to change the about:config preference "layout.css.flexbox.enabled" to
true. Multi-line flexbox are supported since Firefox 28.