Prevent background scrolling in modals and overlays
Disable pull-to-refresh on mobile devices
Create independent scroll areas in complex layouts
Control horizontal and vertical overscroll separately
Improve UX for chat interfaces and sidebar navigation
Introduction to Overscroll Behavior
The overscroll-behavior property controls what happens when you scroll to the edge of a scrollable container. By default, scrolling continues to the parent element (scroll chaining), but you can prevent this to create better modal experiences, disable pull-to-refresh, and build independent scroll areas.
This property is essential for modern web applications with nested scrollable areas, modals, chat interfaces, and mobile-optimized layouts where unintended scrolling can disrupt the user experience.
Understanding the Values
The overscroll-behavior property accepts three values, each controlling scroll chaining and bounce effects differently.
/* Default behavior - scroll chains to parent */
.container {
overscroll-behavior: auto;
/* When reaching edge, parent scrolls */
}
/* Prevent scroll chaining, allow bounce effects */
.modal {
overscroll-behavior: contain;
/* Scrolling stops at container edge */
/* Still allows bounce/overscroll effects (iOS, etc.) */
}
/* Prevent everything */
.strict {
overscroll-behavior: none;
/* No scroll chaining AND no bounce effects */
/* Most restrictive */
}
Modal Scroll Locking
The most common use case for overscroll-behavior is preventing background page scrolling when a modal is open.
/* Modal body with scroll lock */
.modal-body {
overflow-y: auto;
overscroll-behavior: contain; /* Prevent background scroll */
max-height: 80vh;
}
/* Bonus: prevent horizontal overscroll too */
.modal-body {
overscroll-behavior-y: contain; /* Vertical only */
overscroll-behavior-x: none; /* Horizontal */
/* Or shorthand: */
overscroll-behavior: none contain; /* x y */
}
Disabling Pull-to-Refresh
Mobile browsers often have pull-to-refresh enabled by default. Use overscroll-behavior to disable it for web apps where this gesture conflicts with your UI.
/* Disable pull-to-refresh on mobile */
body {
overscroll-behavior-y: contain;
/* No pull-to-refresh */
/* Still allows side-swipe navigation */
}
/* For full-screen apps or games */
html, body {
overscroll-behavior: none;
/* Disable all overscroll effects */
/* Complete control */
}
Chat Interfaces
Chat applications need independent scroll areas for the message list without affecting the overall page scroll.
.chat-messages {
height: 400px;
overflow-y: auto;
overscroll-behavior-y: contain; /* Keep scroll within chat */
}
/* Prevents:
- Scrolling the page when reaching top of chat history
- Scrolling the page when reaching bottom of chat
- Pull-to-refresh accidentally triggering
*/
Sidebar Navigation
Create independent scroll areas for sidebars and main content in application layouts.
.sidebar {
overflow-y: auto;
overscroll-behavior: contain; /* Independent scrolling */
}
.main-content {
overflow-y: auto;
/* Each scroll area is independent */
}
/* Common in:
- Documentation sites with sticky sidebars
- Admin dashboards
- Email clients
- File managers
*/
Nested Scroll Containers
Prevent scroll chaining in nested scrollable areas like dropdowns within scrollable pages.
/* Outer scroll container */
.page-content {
overflow-y: auto;
}
/* Inner dropdown menu */
.dropdown-menu {
overflow-y: auto;
max-height: 300px;
overscroll-behavior: contain; /* Don't chain to page */
}
/* Use cases:
- Dropdown menus with scrolling
- Embedded widgets
- Code editors within pages
- Data tables with scrolling
*/
Directional Control
Control horizontal and vertical overscroll behavior independently with directional properties.