Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2019.

The scroll-margin-block-start property defines the margin of the scroll snap area at the start of the block dimension that is used for snapping this box to the snapport. The scroll snap area is determined by taking the transformed border box, finding its rectangular bounding box (axis-aligned in the scroll container's coordinate space), then adding the specified outsets.

Try it


/* <length> values */
scroll-margin-block-start: 10px;
scroll-margin-block-start: 1em;

/* Global values */
scroll-margin-block-start: inherit;
scroll-margin-block-start: initial;
scroll-margin-block-start: revert;
scroll-margin-block-start: revert-layer;
scroll-margin-block-start: unset;



An outset from the block start edge of the scroll container.

Formal definition

Initial value0
Applies toall elements
Computed valueas specified
Animation typeby computed value type

Formal syntax

scroll-margin-block-start = 


CSS Scroll Snap Module Level 1
# margin-longhands-logical

Browser compatibility

BCD tables only load in the browser

See also