align-items property specifies the default
align-self value for all boxes (including anonymous boxes) participating in this box's formatting context.
The alignment is similar to
justify-content but in the perpendicular direction.
To align individual items, use the
align-self property. This will override the
align-items property for the specified flex item with which it is applied.
- The cross-start margin edge of the flex item is placed flush with the cross-start edge of the line.
- The cross-end margin edge of the flex item is placed flush with the cross-end edge of the line.
- The flex item's margin box is centered in the cross axis within the line. (If the cross size of the flex line is less than that of the flex item, 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 baseline and its cross-start margin edge is placed flush against the cross-start edge of the line.
If the flex item's inline axis is the same as the cross axis, this value is identical to
- Flex items are stretched such as the cross-size of the item's margin box is the same as the line while still respecting
In addition, all CSS properties also accept the following CSS-wide keyword values as the sole component of their property value:
- Represents the value specified as the property's initial value.
- Represents the computed value of the property on the element's parent.
- This value acts as either
initial, depending on whether the property is inherited or not. In other words, it sets all properties to their parent value if they are inheritable or to their initial value if not inheritable.
Basic Property Information
- Initial Value
- Applies To
- Flex containers
- Computed Value
- Specified value
Working Example within an HTML Document
Flexbox refers to the Flexible Box Layout module introduced in CSS3. Flex items are placed within a flex container. A flex container is an element with either
display: flex or
In the flex layout model, the children of a flex container can be laid out in any direction, and can "flex" their sizes, either growing to fill unused space or shrinking to avoid overflowing the parent.
For more information on flex items, see the
align-itemsproperty is defined in the CSS Flexible Box Layout Module Level 1 (W3C Candidate Recommendation, 26 May 2016)
- It is also being redefined in CSS Box Alignment Module Level 3 (W3C Working Draft).
The following table provided by Caniuse.com shows the level of browser support for this feature.
For maximum browser compatibility many web developers add browser-specific properties by using extensions such as
-webkit- for Safari, Google Chrome, and Opera (newer versions),
-ms- for Internet Explorer,
-moz- for Firefox,
-o- for older versions of Opera etc. As with any CSS property, if a browser doesn't support a proprietary extension, it will simply ignore it.
This practice is not recommended by the W3C, however in many cases, the only way you can test a property is to include the CSS extension that is compatible with your browser.
The major browser manufacturers generally strive to adhere to the W3C specifications, and when they support a non-prefixed property, they typically remove the prefixed version. Also, W3C advises vendors to remove their prefixes for properties that reach Candidate Recommendation status.
Many developers use Autoprefixer, which is a postprocessor for CSS. Autoprefixer automatically adds vendor prefixes to your CSS so that you don't need to. It also removes old, unnecessary prefixes from your CSS.
You can also use Autoprefixer with preprocessors such as Less and Sass.