Animations & Transitions

CSS Transitions vs Animations

Transitions animate property changes from one state to another (usually triggered by hover, focus, or class change). Animations use keyframes to define complex, multi-step animations that can run automatically or loop infinitely.

CSS Transitions

Transitions make property changes smooth instead of instant. Try hovering over these examples:

.button {
  background: #3b82f6;
  transition: all 0.3s ease;
}
.button:hover {
  background: #2563eb;
  transform: scale(1.05);
}

.box-1 {
  transition: all 0.5s ease;
}
.box-1:hover {
  border-radius: 50%;
  background: #9333ea;
  transform: rotate(180deg);
}

.box-2 {
  transition: width 0.7s ease;
}
.box-2:hover {
  width: 200px;
}

Timing Functions

Timing functions control the speed curve of animations:

Hover over the colored boxes to see timing differences

CSS Keyframe Animations

Keyframes define complex animations with multiple stages:

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.element {
  animation: fadeIn 2s ease-out;
}

Common Animation Patterns

@keyframes spin {
  to { transform: rotate(360deg); }
}
.spinner {
  animation: spin 1s linear infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}
.bounce {
  animation: bounce 0.6s ease infinite;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-10px); }
  75% { transform: translateX(10px); }
}
.error { animation: shake 0.3s ease; }

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.1); }
}
.pulse {
  animation: pulse 1.5s ease infinite;
}

Skeleton Loading Effect

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}
.skeleton {
  background: linear-gradient(
    90deg,
    #f0f0f0 25%,
    #e0e0e0 50%,
    #f0f0f0 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

Transform Property

The transform property is the most performant way to animate movement, rotation, and scaling:

transform: translateX(50px);
transform: translateY(50px);

transform: rotate(45deg);

transform: scale(1.5);

transform: translateX(16px) 
  rotate(12deg) scale(1.1);

Animation Properties

/* Animation timing */
animation-duration: 1s;
animation-delay: 0.5s;

/* Iteration */
animation-iteration-count: 1;       /* once */
animation-iteration-count: 3;       /* 3 times */
animation-iteration-count: infinite; /* forever */

/* Direction */
animation-direction: normal;         /* 0% → 100% */
animation-direction: reverse;        /* 100% → 0% */
animation-direction: alternate;      /* ping-pong */

/* Fill mode (what happens before/after) */
animation-fill-mode: none;      /* reset after */
animation-fill-mode: forwards;  /* keep end state */
animation-fill-mode: backwards; /* apply start before delay */
animation-fill-mode: both;      /* both */

/* Shorthand */
animation: fadeIn 1s ease-out 0.5s forwards;

Accessibility: Reduced Motion

Some users have vestibular disorders and need reduced motion. Always respect this preference:

/* Respect user preference */
@media (prefers-reduced-motion: reduce) {
  *,

  

    
Learn More
    

      
        
MDN: CSS Animations
        
Guide to creating and controlling CSS animations.
      
      
        
Animista
        
CSS animation library and generator.
      
    
  
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Or per-element */
@media (prefers-reduced-motion: reduce) {
  .animated-element {
    animation: none;
  }
}