CSS justify-content
The CSS justify-content
property controls alignment of a box's content along the main/inline axis within its content box.
The justify-content
property aligns flex items along the main axis of the current line of the flex container. It defines how space is distributed between and around flex items.
The alignment is done after any flexible lengths and any auto margins have been resolved. Therefore, flex-grow
will need to be 0
, otherwise the justify-content
property will have no effect.
Syntax
Possible Values
flex-start
- Flex items are packed toward the start of the line.
flex-end
- Flex items are packed toward the end of the line.
center
- Flex items are packed toward the center of the line.
space-between
- Flex items are evenly distributed in the line.
space-around
- Same as
space-between
, but with half-size spaces on either end.
In addition, all CSS properties also accept the following CSS-wide keyword values as the sole component of their property value:
initial
- Represents the value specified as the property's initial value.
inherit
- Represents the computed value of the property on the element's parent.
unset
- This value acts as either
inherit
orinitial
, 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
flex-start
- Applies To
- Flex containers
- Inherited?
- No
- Media
- Visual
- Computed Value
- Specified value
- Animatable
- No
Example Code
Basic CSS
Working Example within an HTML Document
CSS Specifications
- The
justify-content
property is defined in 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).
About Flexbox
Flexbox refers to the Flexible Box Layout module introduced in CSS3. A flex container is an element with either display: flex
or display: inline-flex
.
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 flex
property.
Browser Support
The following table provided by Caniuse.com shows the level of browser support for this feature.
Vendor Prefixes
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.