overscroll-behavior

The overscroll-behavior CSS property sets what a browser does when reaching the boundary of a scrolling area. It's a shorthand for overscroll-behavior-x and overscroll-behavior-y.

By default, mobile browsers tend to provide a "bounce" effect or even a page refresh when the top or bottom of a page (or other scroll area) is reached. You may also have noticed that when you have a dialog box with scrolling content on top of a page of scrolling content, once the dialog box's scroll boundary is reached, the underlying page will then start to scroll — this is called scroll chaining.

In some cases these behaviors are not desirable. You can use overscroll-behavior to get rid of unwanted scroll chaining and the browser's Facebook/Twitter app-inspired "pull to refresh"-type behavior.

Syntax

/* Keyword values */
overscroll-behavior: auto; /* default */
overscroll-behavior: contain;
overscroll-behavior: none;

/* Two values */
overscroll-behavior: auto contain;

/* Global values */
overscroll-behavior: inherit;
overscroll-behavior: initial;
overscroll-behavior: revert;
overscroll-behavior: unset;

The overscroll-behavior property is specified as one or two keywords chosen from the list of values below.

Two keywords specifies the overscroll-behavior value on the x and y axes respectively. If only one value is specified, both x and y are assumed to have the same value.

Values

auto

The default scroll overflow behavior occurs as normal.

contain

Default scroll overflow behavior is observed inside the element this value is set on (e.g. "bounce" effects or refreshes), but no scroll chaining occurs to neighboring scrolling areas, e.g. underlying elements will not scroll.

none

No scroll chaining occurs to neighboring scrolling areas, and default scroll overflow behavior is prevented.

Formal definition

Initial valueauto
Applies tonon-replaced block-level elements and non-replaced inline-block elements
Inheritedno
Computed valueas each of the properties of the shorthand:
Animation typediscrete

Formal syntax

[ contain | none | auto ]{1,2}

Examples

Preventing an underlying element from scrolling

In our overscroll-behavior example (see the source code also), we present a full-page list of fake contacts, and a dialog box containing a chat window.

A popup chat window titled 'Active chat', showing a conversation between Chris and Bob. Behind the chat window is a contact list titled 'overscroll-behavior demo'.

Both of these areas scroll; normally if you scrolled the chat window until you hit a scroll boundary, the underlying contacts window would start to scroll too, which is not desirable. This can be stopped using overscroll-behavior-y (overscroll-behavior would also work) on the chat window, like this:

.messages {
  height: 220px;
  overflow: auto;
  overscroll-behavior-y: contain;
}

We also wanted to get rid of the standard overscroll effects when the contacts are scrolled to the top or bottom (e.g. Chrome on Android refreshes the page when you scroll past the top boundary). This can be prevented by setting overscroll-behavior: none on the <html> element:

html {
  margin: 0;
  overscroll-behavior: none;
}

Specifications

Specification
CSS Overscroll Behavior Module Level 1
# overscroll-behavior-properties

Browser compatibility

BCD tables only load in the browser

See also