Motion design isn't just decoration—it's functional storytelling. Master GSAP, Lottie, and CSS animations.
Motion as Functional Communication
Motion design is often dismissed as decorative flourish, but purposeful animation serves critical functional roles: guiding attention, indicating relationships, providing feedback, and creating spatial understanding.
When a user clicks a button and it responds with subtle animation, that's feedback. When elements slide in as you scroll, that's narrative pacing. When a menu expands smoothly, that's spatial communication. Every animation should serve a purpose beyond looking cool.
The Modern Animation Toolkit
Choosing the right animation tool for the job is crucial. Each has strengths for different use cases.
GSAP: Professional-grade JavaScript animation library for complex, performant sequences
Lottie: JSON-based animations from After Effects for designer-friendly motion graphics
CSS Animations: Simple transforms and transitions with minimal overhead
Framer Motion: React-specific animation library with great gesture support
Three.js: 3D animations and WebGL experiences
ScrollTrigger: Scroll-based animation timing and orchestration
Performance Considerations
Animation can enhance or destroy user experience depending on performance. The key is understanding what triggers browser repaints and reflows. Animate transforms and opacity—these are GPU-accelerated and performant. Avoid animating width, height, or position properties.
Use the will-change CSS property judiciously to hint to browsers about upcoming animations. Implement reduced-motion preferences to respect users who prefer less animation. Every animation should feel smooth at 60fps, even on lower-end devices.
"The best animations are the ones users don't consciously notice—they just feel the experience is smooth and intuitive."
Creating Meaningful Motion
Great web animation follows principles from traditional animation: easing, anticipation, follow-through. Linear motion feels robotic. Natural motion has weight and physics—ease-in for objects gaining speed, ease-out for deceleration.
Stagger animations to guide the eye through sequences. Use motion to establish hierarchy—important elements can have more dramatic animations. Keep duration appropriate: 200-500ms for UI feedback, longer for narrative moments. Test extensively to ensure animations enhance rather than distract.
