withSpring

The withSpring modifier creates natural, physics-based animations using spring physics. It's perfect for UI elements that should feel alive and responsive, like buttons, cards, modals, and interactive components.

Why Use withSpring?

Spring animations feel natural because they simulate real-world physics:

• Bounce - Natural overshoot and settle
• Responsive - Adapts to different screen sizes and devices
• Smooth - No jarring stops or starts
• Performant - Optimized for 60fps animations

Basic Syntax

withSpring(toValue, options?)

Parameters

• toValue (required): The target value. Can be a number, string, object, or array.
• options (optional): Configuration object for fine-tuning the spring behavior.

Simple Example

The simplest spring animation:

import { useValue, withSpring, animate } from 'react-ui-animate';

function MyComponent() {
  const [width, setWidth] = useValue(100);

  return (
    <>
      <button onClick={() => setWidth(withSpring(200))}>
        Expand
      </button>
      <animate.div style={{ width, height: 100, background: '#60a5fa' }} />
    </>
  );
}

Preview

Configuration Options

Fine-tune your spring animations with these options:

Option	Type	Default	Description
stiffness	number	158	How "stiff" the spring is. Higher = faster, more bouncy
damping	number	20	How quickly the spring loses energy. Higher = less bouncy, more controlled
mass	number	1	The "weight" of the spring. Higher = slower, more inertia
onStart	() => void	-	Called when animation starts
onChange	(value) => void	-	Called on every frame with current value
onComplete	() => void	-	Called when animation finishes

Understanding Spring Parameters

Stiffness - Controls speed and bounce

• Low (50-100): Slow, gentle motion
• Medium (150-200): Balanced, natural feel (default)
• High (300+): Fast, snappy motion

Damping - Controls bounce and overshoot

• Low (5-15): Very bouncy, lots of overshoot
• Medium (20-30): Balanced bounce (default)
• High (40+): Minimal bounce, controlled motion

Mass - Controls inertia

• Low (0.5-1): Light, quick response (default)
• Medium (1-2): Balanced
• High (3+): Heavy, slow to start/stop

Real-World Examples

Example 1: Button Hover Effect

Create a responsive button that springs on hover:

function SpringButton() {
  const [scale, setScale] = useValue(1);

  return (
    <animate.button
      onMouseEnter={() => setScale(withSpring(1.1, { stiffness: 300 }))}
      onMouseLeave={() => setScale(withSpring(1))}
      style={{
        scale,
        padding: '10px 20px',
        background: '#60a5fa',
        border: 'none',
        borderRadius: 4,
      }}
    >
      Hover me
    </animate.button>
  );
}

Example 2: Modal Animation

Smooth modal entrance with spring:

function Modal({ isOpen, onClose }) {
  const [scale, setScale] = useValue(0);

  useEffect(() => {
    if (isOpen) {
      setScale(withSpring(1, { stiffness: 200, damping: 25 }));
    } else {
      setScale(withSpring(0));
    }
  }, [isOpen]);

  return (
    <div style={{ position: 'fixed', inset: 0, background: 'rgba(0,0,0,0.5)' }}>
      <animate.div
        style={{
          scale,
          opacity: scale,
          background: 'white',
          padding: 20,
          borderRadius: 8,
        }}
      >
        Modal Content
        <button onClick={onClose}>Close</button>
      </animate.div>
    </div>
  );
}

Example 3: Card Flip Animation

Animate multiple properties together:

function FlipCard() {
  const [rotation, setRotation] = useValue(0);
  const [scale, setScale] = useValue(1);

  const flip = () => {
    setRotation(withSpring(rotation + 180));
    setScale(withSpring(0.95, { stiffness: 300 }));
    setTimeout(() => {
      setScale(withSpring(1));
    }, 200);
  };

  return (
    <animate.div
      onClick={flip}
      style={{
        rotate: rotation,
        scale,
        width: 200,
        height: 200,
        background: '#60a5fa',
        borderRadius: 8,
      }}
    >
      Click to flip
    </animate.div>
  );
}

Animating Multiple Values

Spring works great with objects and arrays:

const [position, setPosition] = useValue({ x: 0, y: 0 });

// Animate both x and y together
setPosition(withSpring({ x: 100, y: 100 }));

Preview

Using Callbacks

React to animation lifecycle events:

function AnimatedCard() {
  const [x, setX] = useValue(0);

  const animate = () => {
    setX(withSpring(200, {
      onStart: () => {
        console.log('Animation started');
        // Disable button, show loading, etc.
      },
      onChange: (value) => {
        // Track progress, update other values
        console.log('Current position:', value);
      },
      onComplete: () => {
        console.log('Animation finished');
        // Re-enable button, hide loading, etc.
      },
    }));
  };

  return (
    <>
      <button onClick={animate}>Animate</button>
      <animate.div style={{ translateX: x, width: 100, height: 100, background: '#60a5fa' }} />
    </>
  );
}

Preset Configurations

Common spring configurations for different use cases:

// Gentle, smooth animation
const gentle = { stiffness: 120, damping: 25 };

// Snappy, quick animation
const snappy = { stiffness: 300, damping: 30 };

// Bouncy, playful animation
const bouncy = { stiffness: 200, damping: 10 };

// Controlled, minimal bounce
const controlled = { stiffness: 180, damping: 35 };

// Usage
setX(withSpring(100, gentle));

Best Practices

✅ Do

• Use withSpring for most UI animations - it feels natural
• Adjust stiffness and damping to match your design language
• Use objects/arrays for coordinated multi-property animations
• Leverage callbacks for side effects and state management

❌ Don't

• Don't use withSpring when you need exact timing (use withTiming instead)
• Don't set extremely high stiffness values (>500) - can cause jank
• Don't forget to handle the animation lifecycle with callbacks when needed
• Don't animate layout properties (width, height) - use transforms instead

Performance Tips

1. Spring is optimized - It's one of the fastest modifiers
2. Use transforms - translateX, scale, rotate are GPU-accelerated
3. Batch updates - Animate multiple properties in one object
4. Avoid layout properties - width, height, top, left cause reflows

Common Patterns

Pattern 1: Quick Bounce

const [scale, setScale] = useValue(1);

const bounce = () => {
  setScale(withSpring(1.2, { stiffness: 400, damping: 15 }));
  setTimeout(() => setScale(withSpring(1)), 150);
};

Pattern 2: Smooth Entrance

const [opacity, setOpacity] = useValue(0);
const [translateY, setTranslateY] = useValue(-20);

useEffect(() => {
  setOpacity(withSpring(1, { stiffness: 200, damping: 25 }));
  setTranslateY(withSpring(0));
}, []);

Pattern 3: Interactive Feedback

const [rotation, setRotation] = useValue(0);

const handleClick = () => {
  setRotation(withSpring(rotation + 360, { stiffness: 300 }));
};

Troubleshooting

Animation feels too slow:

• Increase stiffness (try 200-300)
• Decrease damping slightly

Animation is too bouncy:

• Increase damping (try 25-35)
• Decrease stiffness slightly

Animation doesn't feel smooth:

• Make sure you're using animate.div (or other animate.* components)
• Check that you're not causing re-renders during animation
• Use transforms instead of layout properties

Next Steps

• Learn about withTiming for precise time-based animations
• Explore withSequence to chain spring animations
• Check out useValue for more animation patterns