The scroll-padding-right property controls how far inward from the right edge of a scroll container the browser treats the "safe" or "snapping" area when performing scroll alignment and snap calculations. Rather than changing box geometry or visual padding, it shifts the effective scrollport used for aligning content: targets that are scrolled or snapped into view will be positioned relative to that inset instead of flush against the physical right edge. This makes the property useful when you want a scrolled-to element to stop short of the container edge so it remains visible behind overlays, controls, or other UI elements.

In practice, scroll-padding-right affects the outcome of scroll-snapping and programmatic scrolling operations. When combined with scroll-snap-type, it alters the positions the browser considers valid snap destinations for child elements, effectively moving snap points inward from the right. It also interacts with scripted or user-initiated scrolls (for example, when calling methods that align an element into view), and will change where the element lands without changing its layout. For smooth or animated scrolls, this inward offset determines the final resting position the animation aims for, and it works alongside behavior controls such as scroll-behavior.

Because scroll-padding-right is a physical, right-side property, its meaning can differ when writing mode or direction changes; for writing-mode–independent adjustments you can use the logical equivalent scroll-padding-inline-end. It is distinct from regular box padding - the latter affects layout, background, and hit testing, whereas scroll padding only influences scroll alignment and snapping calculations. Choose the physical form when you specifically need to target the right side regardless of text direction, and the logical form when you want consistent behavior across different writing modes.

Common use cases include leaving space for fixed or sticky UI elements (so focused or snapped items aren't hidden), fine-tuning per-side snap offsets in complex scroll containers, and improving the perceived layout during programmatic scrolling. Keep in mind that the property applies to the scroll container itself; child elements are aligned according to the container’s computed scroll padding, and it does not create extra visual space or alter the position of static layout elements outside of scroll alignment behavior.