CSS Animation Patterns

Overview

CSS animations and transitions provide hardware-accelerated motion for web interfaces using keyframes, transitions, transforms, and modern scroll-driven and view transition APIs. Animate only composite properties (transform, opacity, filter) for smooth 60fps performance, and always respect prefers-reduced-motion.

The browser rendering pipeline has four stages: Style, Layout, Paint, and Composite. Animating composite-only properties skips Layout and Paint entirely, running on the GPU compositor thread. This is the single most important performance principle for CSS animation.

Modern CSS adds two powerful APIs: scroll-driven animations link keyframe progress to scroll position or element visibility instead of time, and the View Transitions API creates snapshot-based animated transitions between DOM states for both SPAs and MPAs.

When to use: Element state changes, page transitions, scroll-linked effects, loading indicators, micro-interactions, route change animations, reveal-on-scroll patterns, parallax effects, progress indicators tied to scroll.

When NOT to use: Complex physics simulations (use a JS animation library), canvas/WebGL rendering, animations requiring frame-by-frame scripted control (use Web Animations API directly), highly interactive drag-and-drop (use pointer events with JS).

Browser Support Summary