overflow-y - CSS: Cascading Style Sheets 编辑

The overflow-y CSS property sets what shows when content overflows a block-level element's top and bottom edges. This may be nothing, a scroll bar, or the overflow content.

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 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.

Syntax

/* Keyword values */
overflow-y: visible;
overflow-y: hidden;
overflow-y: clip;
overflow-y: scroll;
overflow-y: auto;

/* Global values */
overflow-y: inherit;
overflow-y: initial;
overflow-y: unset;

The overflow-y property is specified as a single keyword chosen from the list of values below.

If overflow-x is hidden, scroll or auto and this property is visible (default) it will implicitly compute to auto.

Values

visible

Content is not clipped and may be rendered outside the padding box's top and bottom edges.

hidden

Content is clipped if necessary to fit vertically in the padding box. No scrollbars are provided.

clip

Like for hidden, the content is clipped to the element's padding box. The difference between clip and hidden is that the clip keyword also forbids all scrolling, including programmatic scrolling. The box is not a scroll container, and does not start a new formatting context. If you wish to start a new formatting context, you can use display: flow-root to do so.

scroll

Content is clipped if necessary to fit vertically in the padding box. Browsers display scrollbars whether or not any content is actually clipped. (This prevents scrollbars from appearing or disappearing when the content changes.) Printers may still print overflowing content.

auto

Depends on the user agent. If content fits inside the padding box, it looks the same as visible, but still establishes a new block-formatting context. Desktop browsers provide scrollbars if content overflows.

Formal definition

Initial value	visible
Applies to	Block-containers, flex containers, and grid containers
Inherited	no
Computed value	as specified, except with visible/clip computing to auto/hidden respectively if one of overflow-x or overflow-y is neither visible nor clip
Animation type	discrete

Formal syntax

visible | hidden | clip | scroll | auto

Examples

Setting overflow-y behavior

HTML

<ul>
  <li><code>overflow-y:hidden</code> — hides the text outside the box
  <div id="div1">
    Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
    </div>
  </li>

  <li><code>overflow-y:scroll</code> — always adds a scrollbar
  <div id="div2">
    Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
    </div>
  </li>

  <li><code>overflow-y:visible</code> — displays the text outside the box if needed
  <div id="div3">
    Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
    </div>
  </li>

  <li><code>overflow-y:auto</code> — on most browser, equivalent to <code>scroll</code>
  <div id="div4">
    Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
    </div>
  </li>
</ul>

CSS

#div1,
#div2,
#div3,
#div4 {
  border: 1px solid black;
  width:  250px;
  height: 100px;
}

#div1 { overflow-y: hidden; margin-bottom: 12px;}
#div2 { overflow-y: scroll; margin-bottom: 12px;}
#div3 { overflow-y: visible; margin-bottom: 120px;}
#div4 { overflow-y: auto; margin-bottom: 120px;}

Result

Specifications

Specification	Status	Comment
CSS Overflow Module Level 3 The definition of 'overflow-y' in that specification.	Working Draft

Browser compatibility

BCD tables only load in the browser

See also

• Related CSS properties: text-overflow, white-space, overflow, overflow-x, clip, display