The CSS justify-content
property defines how the browser distributes space between and around content items along the main axis of their container.
/* Positional alignment */ justify-content: center; /* Pack items around the center */ justify-content: start; /* Pack items from the start */ justify-content: end; /* Pack items from the end */ justify-content: flex-start; /* Pack flex items from the start */ justify-content: flex-end; /* Pack flex items from the end */ justify-content: left; /* Pack items from the left */ justify-content: right; /* Pack items from the right */ /* Baseline alignment */ justify-content: baseline; justify-content: first baseline; justify-content: last baseline; /* Distributed alignment */ justify-content: space-between; /* Distribute items evenly The first item is flush with the start, the last is flush with the end */ justify-content: space-around; /* Distribute items evenly Items have a half-size space on either end */ justify-content: space-evenly; /* Distribute items evenly Items have equal space around them */ justify-content: stretch; /* Distribute items evenly Stretch 'auto'-sized items to fit the container */ /* Overflow alignment */ justify-content: safe center; justify-content: unsafe center; /* Global values */ justify-content: inherit; justify-content: initial; justify-content: unset;
The alignment is done after the lengths and auto margins are applied, meaning that, if in a Flexbox layout there is at least one flexible element, with flex-grow
different from 0
, it will have no effect as there won't be any available space.
<div class="grid"> <div class="col"> <div class="row"> <div class="cell"> normal <div class="container normal"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell warning" title="This feature is experimental and may not work in your browser"> stretch <div class="container stretch"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell warning" title="This feature is experimental and may not work in your browser"> baseline <div class="container baseline"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell"> space-between <div class="container space-between"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell"> space-around <div class="container space-around"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell warning" title="This feature is experimental and may not work in your browser"> space-evenly <div class="container space-evenly"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell"> center <div class="container center"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell warning" title="This feature is experimental and may not work in your browser"> start <div class="container start"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell"> flex-start <div class="container flex-start"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell warning" title="This feature is experimental and may not work in your browser"> left <div class="container left"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell warning" title="This feature is experimental and may not work in your browser"> end <div class="container end"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell"> flex-end <div class="container flex-end"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell warning" title="This feature is experimental and may not work in your browser"> right <div class="container right"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell warning" title="This feature is experimental and may not work in your browser"> first baseline <div class="container first-baseline"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell warning" title="This feature is experimental and may not work in your browser"> last baseline <div class="container last-baseline"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell"> safe center <div class="container safe-center"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> <div class="cell"> unsafe center <div class="container unsafe-center"> <div class="item A">A</div> <div class="item B">B</div> <div class="item C">C</div> </div> </div> </div> <div class="note"> The exact behavior of justify-content depends on these properties : <div class="row"> <div class="code flex"> <code>.container {</code> <code> justify-content: /* See above */;</code> <code> display:<select id="display"><option>flex</option><option>grid</option><option>block</option></select>;</code> <code class="flex"> flex-direction:<select id="flexDirection"><option>row</option><option>row-reverse</option><option>column</option><option>column-reverse</option></select>;</code> <code class="flex"> direction:<select id="direction"><option>ltr</option><option>rtl</option></select>;</code> <code class="grd"> grid-template-columns: repeat(auto-fill, 33%);</code> <code>}</code> </div> <div class="code"> <code>.item {</code> <code> width: <select id="width"><option>auto</option><option>1.5em</option></select></code> <code> height: <select id="height"><option>auto</option><option>1.5em</option></select></code> <code> position: <select id="position"><option>static</option><option>absolute</option></select></code> <code>}</code> </div> </div> </div> </div> </div>
html,body { height: 100%; box-sizing: border-box; background: #EEE; } .grid { width: 100%; height: 100%; display: flex; font: 1em monospace; } .row { display: flex; flex: 1 auto; flex-direction: row; flex-wrap: wrap; } .col { display: flex; flex: 1 auto; flex-direction: column; } .cell { margin: .5em; padding: .5em; background-color: #FFF; overflow: hidden; text-align: center; width: 10.5em; } .note { background: #fff3d4; padding: 1em; margin: .5em; font: .8em sans-serif; text-align: left; flex: 1; white-space: nowrap; } .note .row { justify-content: flex-start; margin-top: .5rem; } .code { margin-right: 1em; line-height: 2.5; } code { display: block; } .warning { background: #EEDDDD; } .warning::before { content: "\26A0\FE0F "; } .container { display: flex; background: #000; width: 10.5em; height: 10.5em; max-width: 10.5em; max-height: 10.5em; grid-template-columns: repeat(auto-fill, 33%); overflow: hidden; resize: both; } .item { background: #E4F0F5; box-sizing: border-box; padding: .5em; margin: 1px; } .A { font-size: .8rem; } .B { font-size: 1.8rem; } .C { font-size: 1.3rem; } .normal { justify-content: normal; } .space-between { justify-content: space-between; } .space-around { justify-content: space-around; } .space-evenly { justify-content: space-evenly; } .stretch { justify-content: stretch; } .center { justify-content: center; } .start { justify-content: start; } .end { justify-content: end; } .flex-start { justify-content: flex-start; } .flex-end { justify-content: flex-end; } .left { justify-content: left; } .right { justify-content: right; } .baseline { justify-content: baseline; } .first-baseline { justify-content: first baseline; } .last-baseline { justify-content: last baseline; } .safe-center { justify-content: safe center; } .unsafe-center { justify-content: unsafe center; }
window.addEventListener('load', function () { var select = Array.from(document.querySelectorAll('select')); var container = Array.from(document.querySelectorAll('.container')); var item = Array.from(document.querySelectorAll('.item')); function getData() { return select.reduce(function (obj, field) { obj[field.id] = field.value return obj }, {}); } window.addEventListener('input', function () { var data = getData(); container.forEach(function (c) { c.style.display = data.display; c.style.direction = data.direction; c.style.flexDirection = data.flexDirection; }) item.forEach(function (c) { c.style.width = data.width; c.style.height = data.height; c.style.position = data.position; }) }); })
Initial value | flex-start |
---|---|
Applies to | flex containers |
Inherited | no |
Media | visual |
Computed value | as specified |
Animation type | discrete |
Canonical order | the unique non-ambiguous order defined by the formal grammar |
Syntax
Values
start
- The items are packed flush to each other toward the start edge of the alignment container in the main axis.
end
- The items are packed flush to each other toward the end edge of the alignment container in the main axis.
flex-start
- The items are packed flush to each other toward the edge of the alignment container depending on the flex container's main-start side.
This only applies to flex layout items. For items that are not children of a flex container, this value is treated likestart
. flex-end
- The items are packed flush to each other toward the edge of the alignment container depending on the flex container's main-end side.
This only applies to flex layout items. For items that are not children of a flex container, this value is treated likeend
. center
- The items are packed flush to each other toward the center of the of the alignment container along the main axis.
left
- The items are packed flush to each other toward the left edge of the alignment container. If the property’s axis is not parallel with the inline axis, this value behaves like
start
. right
- The items are packed flush to each other toward the right edge of the alignment container in the appropriate axis. If the property’s axis is not parallel with the inline axis, this value behaves like
start
. baseline
first baseline
last baseline
- Specifies participation in first- or last-baseline alignment: aligns the alignment baseline of the box’s first or last baseline set with the corresponding baseline in the shared first or last baseline set of all the boxes in its baseline-sharing group.
The fallback alignment forfirst baseline
isstart
, the one forlast baseline
isend
. space-between
- The items are evenly distributed within the alignment container along the main axis. The spacing between each pair of adjacent items is the same. The first item is flush with the main-start edge, and the last item is flush with the main-end edge.
space-around
- The items are evenly distributed within the alignment container along the main axis. The spacing between each pair of adjacent items is the same. The empty space before the first and after the last item equals half of the space between each pair of adjacent items.
space-evenly
- The items are evenly distributed within the alignment container along the main axis. The spacing between each pair of adjacent items, the main-start edge and the first item, and the main-end edge and the last item, are all 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 (not proportionally), while still respecting the constraints imposed bymax-height
/max-width
(or equivalent functionality), so that the combined size exactly fills the alignment container along the main axis. safe
- If the size of the item overflows the alignment container, the item is instead aligned as if the alignment mode were
start
. unsafe
- Regardless of the relative sizes of the item and alignment container, the given alignment value is honored.
Formal syntax
flex-start | flex-end | center | space-between | space-around | space-evenly
Example
CSS content
#container { display: flex; justify-content: space-between; /* Can be changed in the live sample */ } #container > div { width: 100px; height: 100px; background: linear-gradient(-45deg, #788cff, #b4c8ff); }
HTML content
<div id="container"> <div></div> <div></div> <div></div> </div> <select id="justifyContent"> <option value="start">start</option> <option value="end">end</option> <option value="flex-start">flex-start</option> <option value="flex-end">flex-end</option> <option value="center">center</option> <option value="left">left</option> <option value="right">right</option> <option value="baseline">baseline</option> <option value="first baseline">first baseline</option> <option value="last baseline">last baseline</option> <option value="space-between" selected>space-between</option> <option value="space-around">space-around</option> <option value="space-evenly">space-evenly</option> <option value="stretch">stretch</option> </select>
JavaScript content
var justifyContent = document.getElementById("justifyContent"); justifyContent.addEventListener("change", function (evt) { document.getElementById("container").style.justifyContent = evt.target.value; });
Result
Specifications
Specification | Status | Comment |
---|---|---|
CSS Box Alignment Module Level 3 The definition of 'justify-content' in that specification. |
Working Draft | Adds the [ first | last ]? baseline, self-start, self-end, start, end, left, right, unsafe | safe values. |
CSS Flexible Box Layout Module The definition of 'justify-content' in that specification. |
Candidate Recommendation | Initial definition |
Browser compatibility
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 291 21 -webkit- | Yes Yes -webkit- | 202 18 —?3 49 -webkit- | 11 | 12.1 | 9 |
space-evenly | 60 | No | 52 | No | No | No |
start and end | Yes5 | No | Yes | No | Yes5 | ? |
left and left | Yes5 | No | 52 Yes5 | Yes5 | Yes5 | ? |
baseline | 57 | No | Yes | No | ? | ? |
first baseline and last baseline | No | No | 52 | No | No | ? |
stretch | 57 | No | 52 | No | 44 | ? |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | Yes1 | Yes | Yes Yes -webkit- | ? | No | 12.1 | ? |
space-evenly | No | No | No | 52 | No | No | No |
start and end | ? | ? | ? | ? | ? | ? | ? |
left and left | ? | ? | ? | 52 Yes5 | ? | ? | ? |
baseline | ? | ? | No | Yes | No | ? | ? |
first baseline and last baseline | ? | ? | No | 52 | ? | ? | ? |
stretch | ? | ? | No | 52 | ? | ? | ? |
1. Older versions of the specification treat absolutely positioned children as though they are 0 by 0 flex items. Later versions of the specification take them out of the flow and set their positions based on align and justify properties. Versions 52 and later implement the new behavior.
2. Before Firefox 27, Firefox supported only single-line flexbox.
3. From version 18: this feature is behind the layout.css.flexbox.enabled
preference (needs to be set to true
). To change preferences in Firefox, visit about:config.
4. From version 48: this feature is behind the layout.css.prefixes.webkit
preference (needs to be set to true
). To change preferences in Firefox, visit about:config.
5. This value is recognized, but has no effect.
See also
- CSS Flexbox Guide: Basic Concepts of Flexbox
- CSS Flexbox Guide: Aligning items in a flex container