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

normal

The items are packed in their default position as if no justify-content value was set.

flex-start

Flex items are packed toward the start of the line.

flex-end

Flex items are packed toward the end of the line.

start

Items are packed toward the start edge of the alignment container in the main axis.

end

Items are packed toward the end edge of the alignment container in the main axis.

left

Items are packed toward the left edge of the alignment container.

right

Items are packed toward the right edge of the alignment container.

center

Items are packed toward the center of the line.

space-between

Items are evenly distributed in the line. The first item is flush with the start edge, and the last item is flush with the end edge.

space-around

Same as space-between, but with half-size spaces on either end.

space-evenly

Items are evenly distributed so that the spacing between any two adjacent items, and the spacing to the edges, is exactly the same.

stretch

If the combined size of the items is less than the size of the alignment container, any auto-sized items have their size increased equally so that the combined size exactly fills the alignment container.

safe

If the size of the item overflows the alignment container, the item is instead aligned as if the alignment mode were start.

unsafe

The given alignment value is honored, regardless of the relative sizes of the item and alignment container.

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 or 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

Example Code

Basic CSS

Working Example within an HTML Document

CSS Specifications

• The justify-content property is defined in CSS Box Alignment Module Level 3.
• It was originally defined in CSS Flexible Box Layout Module Level 1.

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.