align-content

The CSS align-content property defines how the browser distributes space between and around content items along the cross-axis of their container, which is serving as a flexible box container.

/* Positional alignment */
align-content: center;     /* Pack items around the center */
align-content: start;      /* Pack items from the start */
align-content: end;        /* Pack items from the end */
align-content: flex-start; /* Pack flex items from the start */
align-content: flex-end;   /* Pack flex items from the end */
align-content: left;       /* Pack items from the left */
align-content: right;      /* Pack items from the right */
/* Baseline alignment */
align-content: baseline;
align-content: first baseline;
align-content: last baseline;
/* Distributed alignment */
align-content: space-between; /* Distribute items evenly
                                 The first item is flush with the start,
                                 the last is flush with the end */
align-content: space-around;  /* Distribute items evenly
                                 Items have a half-size space
                                 on either end */
align-content: space-evenly;  /* Distribute items evenly
                                 Items have equal space around them */
align-content: stretch;       /* Distribute items evenly
                                 Stretch 'auto'-sized items to fit
                                 the container */
/* Overflow alignment */
align-content: safe center;
align-content: unsafe center;
/* Global values */
align-content: inherit;
align-content: initial;
align-content: unset;

This property has no effect on single line flexible boxes.

Syntax

Values

start

The items are packed flush to each other toward the start edge of the alignment container in the cross axis.

end

The items are packed flush to each other toward the end edge of the alignment container in the cross axis.

flex-start

The items are packed flush to each other toward the edge of the alignment container depending on the flex container's cross-start side.
This only applies to flex layout items. For items that are not children of a flex container, this value is treated like start.

flex-end

The items are packed flush to each other toward the edge of the alignment container depending on the flex container's cross-end side.
This only applies to flex layout items. For items that are not children of a flex container, this value is treated like end.

center

The items are packed flush to each other toward the center of the of the alignment container along the cross axis.

left

The items are packed flush to each other toward the left edge of the alignment container in the cross axis. 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 cross 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 for first baseline is start, the one for last baseline is end.

space-between

The items are evenly distributed within the alignment container along the cross 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 cross 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 cross 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 along the cross axis 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 by max-height/max-width (or equivalent functionality), so that the combined size exactly fills the alignment container along the cross 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 | stretch

Example

CSS

#container {
  height:200px;
  width: 240px;
  align-content: center; /* Can be changed in the live sample */
  background-color: #8c8c8c;
}
.flex {
  display: flex;
  flex-wrap: wrap;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, 50px);
}
div > div {
  box-sizing: border-box;
  border: 2px solid #8c8c8c;
  width: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
}
#item1 {
  background-color: #8cffa0;
  min-height: 30px;
}
#item2 {
  background-color: #a0c8ff;
  min-height: 50px;
}
#item3 {
  background-color: #ffa08c;
  min-height: 40px;
}
#item4 {
  background-color: #ffff8c;
  min-height: 60px;
}
#item5 {
  background-color: #ff8cff;
  min-height: 70px;
}
#item6 {
  background-color: #8cffff;
  min-height: 50px;
  font-size: 30px;
}
select {
  font-size: 16px;
}
.row {
  margin-top: 10px;
}

HTML

<div id="container" class="flex">
  <div id="item1">1</div>
  <div id="item2">2</div>
  <div id="item3">3</div>
  <div id="item4">4</div>
  <div id="item5">5</div>
  <div id="item6">6</div>
</div>
<div class="row">
  <label for="display">display: </label>
  <select id="display">
    <option value="flex">flex</option>
    <option value="grid">grid</option>
  </select>
</div>
<div class="row">
  <label for="values">align-content: </label>
  <select id="values">
    <option value="normal">normal</option>
    <option value="stretch">stretch</option>
    <option value="flex-start">flex-start</option>
    <option value="flex-end">flex-end</option>
    <option value="center" selected>center</option>
    <option value="space-between">space-between</option>
    <option value="space-around">space-around</option>
    <option value="space-evenly">space-evenly</option>
    <option value="start">start</option>
    <option value="end">end</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="safe center">safe center</option>
    <option value="unsafe center">unsafe center</option>
    <option value="safe right">safe right</option>
    <option value="unsafe right">unsafe right</option>
    <option value="safe end">safe end</option>
    <option value="unsafe end">unsafe end</option>
    <option value="safe flex-end">safe flex-end</option>
    <option value="unsafe flex-end">unsafe flex-end</option>
  </select>
</div>

var values = document.getElementById('values');
var display = document.getElementById('display');
var container = document.getElementById('container');
values.addEventListener('change', function (evt) {
  container.style.alignContent = evt.target.value;
});
display.addEventListener('change', function (evt) {
  container.className = evt.target.value;
});

Result

Specifications

Browser compatibility

[1] In addition to the unprefixed support, Gecko 48.0 (Firefox 48.0 / Thunderbird 48.0 / SeaMonkey 2.45) added support for a -webkit prefixed version of the property for web compatibility reasons behind the preference layout.css.prefixes.webkit, defaulting to false. Since Gecko 49.0 (Firefox 49.0 / Thunderbird 49.0 / SeaMonkey 2.46) the preference defaults to true.

[2] The keywords start, end, left, and right are recognized but are not implemented.

[3] Versions prior to Gecko 52 (Firefox 52.0 / Thunderbird 52.0 / SeaMonkey 2.49) already recognize the left and right keywords, but don't implement them.

See also

• Using CSS flexible boxes