CSS Scroll Snap Builder

Configure CSS scroll snap with snap type, alignment, and padding with scrollable live preview.

Tested tool guide Tested browser tools Checked August 16, 2026

What CSS Scroll Snap Builder does and how it behaves

CSS Scroll Snap Builder puts the related container and item settings into one live, scrollable example. Choose the snapping axis and strictness, set item alignment, and adjust scroll padding to see how those values change the resting positions. The frequent surprise is that scroll padding does not create visible space around items. It changes the container's snapping viewport, while scroll-snap-align defines how each snap area is positioned within that viewport.

How the result is produced

Container and item roles

The scroll-snap-type setting belongs to the scroll container and selects the snapping axis and strictness. The scroll-snap-align setting belongs to its snap areas, usually the scrolling items. The preview combines both roles so you can scroll through the example and observe where each item settles. A snap type alone does not define useful item alignment.

Scroll padding

Scroll padding moves the edges of the container's optimal viewing region, which affects the positions used for snapping. It can reserve an offset for something such as a sticky header. It does not add layout spacing, enlarge the container, or create gaps between items. The preview makes this distinction visible by shifting the resting position without changing item spacing.

Good uses

Compare start, center, and end alignment for cards in a horizontally scrolling carousel.
Add a snap offset to a vertical section scroller that sits beneath a sticky header.
Test whether proximity or mandatory snapping feels appropriate for a compact overflow panel.

Limits and checks

The preview is illustrative. Real behavior also depends on the final viewport size, item dimensions, overflow, and browser scrolling input.
Scroll padding changes the snapport, not the visual padding or margin around each scrolling item.
Snapping requires actual overflow on the selected axis. A container that cannot scroll may make valid settings appear ineffective.

Common questions

Why does changing scroll-snap-align appear to do nothing?

Confirm that the example can scroll on the axis selected by scroll-snap-type and that the scrolling items are the snap areas. Alignment cannot create overflow or turn ordinary content into a carousel. Its effect may also be subtle when an item already rests near the same start, center, or end position.

Should I use mandatory or proximity snapping?

There is no universal choice. Mandatory snapping requires the container to settle on a snap position, which suits strongly paged interfaces but can make oversized content awkward to inspect. Proximity snapping lets the browser snap when a position is sufficiently close, so ordinary scrolling remains less constrained. Use the preview to compare both with representative item sizes.

References and verification

The behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.