`overscroll-behavior-block` CSS property

The overscroll-behavior-block CSS property sets the browser's behavior when the block direction boundary of a scrolling area is reached.

See overscroll-behavior for a full explanation.

Syntax

css

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

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

Values

This property is specified as one of the following keyword values:

auto: The default scroll overflow behavior occurs as normal.
contain: Default scroll overflow behavior (e.g., "bounce" effects) is observed inside the element where this value is set. However, no scroll chaining occurs on neighboring scrolling areas; the underlying elements will not scroll. The contain value disables native browser navigation, including the vertical pull-to-refresh gesture and horizontal swipe navigation.
none: No scroll chaining occurs to neighboring scrolling areas, and default scroll overflow behavior is prevented.

Formal definition

Initial value	`auto`
Applies to	non-replaced block-level elements and non-replaced inline-block elements
Inherited	no
Computed value	as specified
Animation type	discrete

Formal syntax

overscroll-behavior-block = 
  contain  |
  none     |
  auto     |
  chain

Examples

undefined

Preventing block overscrolling

In this demo we have two block-level boxes, one inside the other. The outer box has a large height set on it so the page will scroll vertically. The inner box has a small width (and height) set on it so it sits comfortably inside the viewport, but its content is given a large height so it will also scroll vertically.

By default, when the inner box is scrolled and a scroll boundary is reached, the whole page will begin to scroll, which is probably not what we want. To avoid this happening in the block direction, we've set overscroll-behavior-block: contain on the inner box.

HTML

html

<main>
  <div>
    <div>
      <p>
        <code>overscroll-behavior-block</code> has been used to make it so that
        when the scroll boundaries of the yellow inner box are reached, the
        whole page does not begin to scroll.
      </p>
    </div>
  </div>
</main>

CSS

css

main {
  height: 3000px;
  width: 500px;
  background-color: white;
  background-image: repeating-linear-gradient(
    to bottom,
    transparent 0px,
    transparent 19px,
    rgb(0 0 0 / 50%) 20px
  );
}

main > div {
  height: 300px;
  width: 400px;
  overflow: auto;
  position: relative;
  top: 50px;
  left: 50px;
  overscroll-behavior-block: contain;
}

div > div {
  height: 1500px;
  width: 100%;
  background-color: yellow;
  background-image: repeating-linear-gradient(
    to bottom,
    transparent 0px,
    transparent 19px,
    rgb(0 0 0 / 50%) 20px
  );
}

p {
  padding: 10px;
  background-color: rgb(255 0 0 / 50%);
  margin: 0;
  width: 340px;
  position: relative;
  top: 10px;
  left: 10px;
}

Result

Specifications

CSS Overscroll Behavior Module Level 1

overscroll-behavior-block CSS property