CSS overflow

<!doctype html>
<title>Example</title>
<style>
  div {
    width: 50vw;
    height: 50vh;
    border: 1vw solid orange;
    font-size: 5vw;
    padding: 5vw;
    margin: auto;
    overflow: auto;
  }
</style>
<div>This div is styled using the CSS overflow property. The contents are too large to fit inside the div. Try changing the value to see what happens to the content.</div>

The CSS overflow property allows you to determine what to when a box is too small for its contents. You can create scroll bars, hide the contents, or automatically expand the box.

As of CSS3, the overflow property is a shorthand property for the overflow-x and overflow-y properties (those properties were only introduced in CSS3). The overflow property allows you to set both of those properties at once.

Syntax

Possible Values

The overflow property is shorthand, and accepts one or two keywords (below). If it has one keyword, that keyword sets both overflow-x and overflow-y; if it has two keywords, it sets overflow-x to the first and overflow-y to the second

visible: Specifies that the content should not be clipped. In other words, it should be displayed outside the content box.
hidden: Specifies that the content is clipped (i.e. the parts that extend beyond the content box are hidden), and no scroll bars (or other scrolling mechanism) are supplied.
scroll: Specifies that the content box should provide scroll bars (or other scrolling mechanism) regardless of whether the content is clipped or not.
auto: Specifies that the content box should provide scroll bars (or other scrolling mechanism) only when the content overflows (i.e. is too big to fit within the content box).

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.

New Values

The CSS basic box model adds two keywords to the overflow properties:

no-display: When the content doesn't fit in the content box, the whole box is removed, as if display: none were specified.
no-content: When the content doesn't fit in the content box, the whole content is hidden, as if visibility: hidden were specified.

The CSS Overflow Module Level 3 adds only one keyword, defined as follows:

clip: Like hidden, this value indicates that the box's content is clipped to its padding box and that no scrolling user interface should be provided by the UA to view the content outside the clipping region. In addition, unlike overflow: hidden which still allows programmatic scrolling, overflow: clip forbids scrolling entirely, through any mechanism, and therefore the box is not a scroll container.

However these two specifications are still in draft status and these values are experimental so avoid using them until they become more stable and gain better browser support.

General Information

Initial Value

See individual properties

Applies To

The exact wording depends on the spec:

CSS2: Block containers.
CSS basic box model: Non-replaced block-level elements and non-replaced 'inline-block' elements.
CSS Overflow Module Level 3: Block containers, flex containers, and grid containers.

Inherited?

Media

Visual

Example Code

Official Specifications

CSS Overflow Module Level 3 (W3C Working Draft, 31 May 2016)
CSS Overflow Module Level 3 (Editor's Draft)
CSS basic box model (W3C Working Draft 9 August 2007)
CSS basic box model (Editor's Draft)
CSS Level 2.1 (W3C Recommendation 07 June 2011)

Web.QHMIT.com