CSS justify-content property defines how the browser distributes space between and around content items along the main-axis of a flex container, and the inline axis of a grid container.

The interactive example below demonstrates some of the values using Grid Layout.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

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.

句法

/* 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 does not take baseline values */
/* Normal alignment */
justify-content: normal;
/* 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;
					

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 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 main-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 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 .
normal
The items are packed in their default position as if no justify-content value was set. This value behaves as stretch in grid and flex containers.
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 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 along the main 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 main axis.

注意: stretch is not supported by flexible boxes (flexbox).

safe
Used alongside an alignment keyword. If the chosen keyword means that the item overflows the alignment container causing data loss, the item is instead aligned as if the alignment mode were start .
unsafe

Used alongside an alignment keyword. Regardless of the relative sizes of the item and alignment container, and regardless of whether overflow which causes data loss might happen, the given alignment value is honored.

形式定义

初始值 normal
适用于 flex containers
继承 no
计算值 如指定
动画类型 discrete

形式句法

normal | <content-distribution> | <overflow-position>? [ <content-position> | left | right ]

where
<content-distribution> = space-between | space-around | space-evenly | stretch
<overflow-position> = unsafe | safe
<content-position> = center | start | end | flex-start | flex-end

范例

Setting flex item distribution

CSS

#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

<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

var justifyContent = document.getElementById("justifyContent");
justifyContent.addEventListener("change", function (evt) {
  document.getElementById("container").style.justifyContent =
      evt.target.value;
});
					

结果

规范

规范 状态 注释
CSS Box Alignment Module Level 3
The definition of 'justify-content' in that specification.
工作草案 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.
候选推荐 初始定义

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Support in Flex layout

更新 GitHub 上的兼容性数据
Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
Supported in Flex Layout Chrome 完整支持 52
完整支持 52
部分支持 29 注意事项
注意事项 Older versions of the specification treat absolute positioned children as though they are a 0 by 0 flex item. Later specification versions take the children out of the flow and set their positions based on align and justify properties. Chrome implements the new behavior beginning with Chrome 52.
完整支持 Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
Edge 完整支持 12 Firefox 完整支持 20 注意事项
完整支持 20 注意事项
注意事项 Before Firefox 27, Firefox supported only single-line flexbox.
不支持 18 — 20 Disabled
Disabled From version 18 until version 20 (exclusive): this feature is behind the layout.css.flexbox.enabled preference (needs to be set to true ). To change preferences in Firefox, visit about:config.
preference (needs to be set to ). To change preferences in Firefox, visit about:config.
IE 完整支持 11 Opera 完整支持 12.1 Safari 完整支持 9 WebView Android 完整支持 52
完整支持 52
部分支持 4.4 注意事项
注意事项 Older versions of the specification treat absolute positioned children as though they are a 0 by 0 flex item. Later specification versions take the children out of the flow and set their positions based on align and justify properties. Chrome implements the new behavior beginning with Chrome 52.
完整支持 Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
Chrome Android 完整支持 52
完整支持 52
部分支持 29 注意事项
注意事项 Older versions of the specification treat absolute positioned children as though they are a 0 by 0 flex item. Later specification versions take the children out of the flow and set their positions based on align and justify properties. Chrome implements the new behavior beginning with Chrome 52.
完整支持 Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
Firefox Android 完整支持 20 注意事项
完整支持 20 注意事项
注意事项 Before Firefox 27, Firefox supported only single-line flexbox.
不支持 18 — 20 Disabled
Disabled From version 18 until version 20 (exclusive): this feature is behind the layout.css.flexbox.enabled preference (needs to be set to true ). To change preferences in Firefox, visit about:config.
preference (needs to be set to ). To change preferences in Firefox, visit about:config.
Opera Android 完整支持 12.1 Safari iOS 完整支持 9 Samsung Internet Android 完整支持 6.0
完整支持 6.0
部分支持 2.0 注意事项
注意事项 Older versions of the specification treat absolute positioned children as though they are a 0 by 0 flex item. Later specification versions take the children out of the flow and set their positions based on align and justify properties. Chrome implements the new behavior beginning with Chrome 52.
完整支持 Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
baseline Chrome 完整支持 57 Edge 完整支持 79 Firefox 不支持 45 — 60 注意事项
不支持 45 — 60 注意事项
注意事项 justify-content no longer accepts baseline values
IE 不支持 No Opera 完整支持 44 Safari 不支持 No WebView Android 完整支持 57 Chrome Android 完整支持 57 Firefox Android 不支持 45 — 60 注意事项
不支持 45 — 60 注意事项
注意事项 justify-content no longer accepts baseline values
Opera Android 完整支持 43 Safari iOS 不支持 No Samsung Internet Android 完整支持 7.0
first baseline and last baseline Chrome 不支持 No Edge 不支持 No Firefox 不支持 52 — 60 注意事项
不支持 52 — 60 注意事项
注意事项 justify-content no longer accepts baseline values
IE 不支持 No Opera 不支持 No Safari 不支持 No WebView Android 不支持 No Chrome Android 不支持 No Firefox Android 不支持 52 — 60 注意事项
不支持 52 — 60 注意事项
注意事项 justify-content no longer accepts baseline values
Opera Android 不支持 No Safari iOS 不支持 No Samsung Internet Android 不支持 No
left and right Chrome 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Edge 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Firefox 完整支持 52 IE 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Opera 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Safari 完整支持 9 WebView Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Chrome Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Firefox Android 完整支持 52 Opera Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Safari iOS 完整支持 9 Samsung Internet Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
safe and unsafe Chrome 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Edge 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Firefox 完整支持 63 IE 不支持 No Opera 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Safari 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
WebView Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Chrome Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Firefox Android 完整支持 63 Opera Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Safari iOS 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Samsung Internet Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
space-evenly Chrome 完整支持 60 Edge 完整支持 79 Firefox 完整支持 52 IE 不支持 No Opera 完整支持 47 Safari 完整支持 11 WebView Android 完整支持 60 Chrome Android 完整支持 60 Firefox Android 完整支持 52 Opera Android 完整支持 44 Safari iOS 完整支持 11 Samsung Internet Android 完整支持 8.0
start and end Chrome 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Edge 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Firefox 完整支持 45 IE 不支持 No Opera 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Safari 完整支持 9 WebView Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Chrome Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Firefox Android 完整支持 45 Opera Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
Safari iOS 完整支持 9 Samsung Internet Android 不支持 No 注意事项
不支持 No 注意事项
注意事项 This value is recognized, but has no effect.
stretch Chrome 完整支持 57 Edge 完整支持 79 Firefox 完整支持 52 IE 不支持 No Opera 完整支持 44 Safari 完整支持 9 WebView Android 完整支持 57 Chrome Android 完整支持 57 Firefox Android 完整支持 52 Opera Android 完整支持 43 Safari iOS 完整支持 9 Samsung Internet Android 完整支持 7.0

图例

完整支持

完整支持

不支持

不支持

见实现注意事项。

见实现注意事项。

用户必须明确启用此特征。

用户必须明确启用此特征。

要求使用供应商前缀或不同名称。

要求使用供应商前缀或不同名称。

Support in Grid layout

更新 GitHub 上的兼容性数据
Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
Supported in Grid Layout Chrome 完整支持 57 Edge 完整支持 16 Firefox 完整支持 52 IE 不支持 No Opera 完整支持 44 Safari 完整支持 10.1 WebView Android 完整支持 57 Chrome Android 完整支持 52 Firefox Android 完整支持 52 Opera Android 完整支持 43 Safari iOS 完整支持 10.3 Samsung Internet Android 完整支持 6.2

图例

完整支持

完整支持

不支持

不支持

另请参阅

元数据

  • 最后修改:
  1. CSS
  2. CSS 参考
  3. CSS Box Alignment
  4. 指南
    1. Box alignment for block, absolutely positioned and table layout
    2. Box alignment in Flexbox
    3. Box alignment in Multi-column Layout
    4. Box alignment in grid layout
  5. 特性
    1. align-content
    2. align-items
    3. align-self
    4. column-gap (grid-column-gap)
    5. gap (grid-gap)
    6. justify-content
    7. justify-items
    8. justify-self
    9. place-content
    10. place-items
    11. place-self
    12. row-gap (grid-row-gap)

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