17 Intersection Observer API Examples

This is a Smooth 3D Scroll-Driven Reveal. It replaces the native scroll behavior with a custom, momentum-based scrolling engine that orchestrates complex 3D transforms. Its function is to create a gallery experience where images feel weightless, tilting and translating in 3D space based on their velocity and position relative to the viewport.

This 3D Rotating iOS Time Picker recreates the tactile feel of native mobile controls on the web. It features three independently rotating wheels (Hours, Minutes, Meridiem) that snap into place with satisfying physics. The component leverages the cutting-edge Scroll-driven Animations API for buttery-smooth performance on supported browsers, while seamlessly falling back to GSAP for others. The 3D perspective creates a “drum” effect where numbers fade and rotate away as they leave the center view.

The Sticky Observer Navigation is a performance-first header component designed for modern landing pages. It uses an elegant dark-blue color palette with “Abril Fatface” typography to create a high-contrast, premium look. The navigation intelligently shrinks and hides the central title as the user scrolls, providing more screen real estate for content while maintaining essential link icons within a fixed bar.

A horizontal scrolling gallery where the background color smoothly transitions to match the current image, triggered by the Intersection Observer API.

A visually unique web application that continuously expands its content upon scrolling, demonstrating the synergy between a reactive framework and modern browser APIs for procedural design.

An infinite scroll gallery built with React, fetching images from the Unsplash API. It leverages the native Intersection Observer API via a useCallback ref to detect when the user reaches the bottom of the grid, automatically triggering the next page fetch and state update for a seamless browsing experience.

A convenient navigation for long-reads or documentation that automatically structures content and visually indicates the user’s current section.

A high-quality, atmospheric Trading Card Game (TCG) interface featuring smooth animations, a tangible sense of depth, and “magical” visual effects upon interaction.

A modern, visually appealing content grid that smoothly assembles on scroll, adapting seamlessly to any screen size.

A performant lazy loading solution utilizing the IntersectionObserver API to defer off-screen image loading. The script monitors elements with a lazy-load class, swapping the data-src attribute into src upon viewport entry - buffered by a 200px rootMargin - to optimize bandwidth and initial page load speed while preventing layout shifts via CSS placeholders.

A user-friendly calendar interface that functions seamlessly on both desktop and mobile devices, keeping context (time and day) constantly visible to the user, featuring both horizontal and vertical scrolling.

This infinitely scrolling image grid employs an IntersectionObserver with baton-passing observation to dynamically load content from the Pixabay API, creating cards through DOM manipulation as the user scrolls. JavaScript manages the paginated requests while CSS Grid provides responsive layout adaptation, with custom properties enabling seamless dark/light theme switching and clip-path animations.

A full vertical slider with scroll-snap points. The navigation indicator is dynamically animated using the Intersection Observer API, which tracks when a slide enters the viewport.

See how the Intersection Observer powers the 2D grid navigation: the Scroll Snap logic handles mandatory cell binding, while a JS utility adds support for keyboard arrow navigation and responsive typography using cqi/dvh units.

An elegant text reveal effect that uses the Intersection Observer API for lazy-loading animation upon entering the viewport and relies on GSAP to perform a smooth “wipe” using a scale transformation.

Impressive scroll-triggered element reveal implemented using the native Intersection Observer API and styling based on CSS Custom Properties for cascading animations.

A demo of the scroll zoom effect via dynamic element visibility calculation and utilizing the Intersection Observer API for performance enhancement.