🖱️
Scroll-driven Animation
Scroll-based interactions without JS
Interactions where elements appear or transform on scroll were implemented with IntersectionObserver or scroll event listeners. With the animation-timeline property and scroll()/view() functions, this can be done purely with CSS.
It doesn't block the main thread for excellent performance and can be used for progress bars, parallax effects, scroll-based fade-ins, and more.
How to Apply
1
Define animation with @keyframes
2
Connect to scroll container with animation-timeline: scroll()
3
Use view() to link with element viewport entry/exit
4
Fine-tune animation active range with animation-range
Pros
- ✓ High-performance scroll animations without JavaScript dependency
- ✓ Runs on compositor thread without blocking main thread
Cons
- ✗ Complex scroll logic may still require JavaScript
- ✗ Limited support in Firefox and Safari
Use Cases
Top progress bar showing scroll progress
Applying fade-in animation when sections enter viewport