Medium Animations (300-500ms)

The 300-500ms range is standard animation territory. Long enough to be watched, short enough to not impede flow. The workhorse duration for meaningful motion.

Disney Principles at Medium Duration

All 12 Principles Applicable

Squash & Stretch: Full expression - visible deformation for bouncing, elastic elements. 15-25% stretch feels natural.

Anticipation: Clear preparation - 80-120ms anticipation before main action. Pull back before push forward.

Staging: Multi-element choreography possible - primary action leads, supporting elements follow.

Straight Ahead/Pose to Pose: Pose to pose recommended - define key positions, let easing handle in-betweens.

Follow Through: Essential - overlapping action where parts settle at different rates.

Slow In/Slow Out: Critical for naturalism - both directions need proper easing.

Arcs: Natural motion paths - elements should travel on curves matching real physics.

Secondary Action: Multiple secondary actions - hair follows head, shadow follows object.

Timing: 18-30 frames at 60fps. Enough frames for nuanced motion.

Exaggeration: Full range available - match to brand personality and context.

Solid Drawing: Complex transforms work - 3D rotations, perspective shifts.

Appeal: Character-defining animations - this is where brand personality lives.

Easing Recommendations

/* Smooth, natural motion */
transition: all 400ms cubic-bezier(0.4, 0, 0.2, 1);

/* Expressive entrance */
transition: all 450ms cubic-bezier(0.16, 1, 0.3, 1);

/* Bouncy, playful */
transition: transform 400ms cubic-bezier(0.34, 1.56, 0.64, 1);

/* Dramatic deceleration */
transition: all 350ms cubic-bezier(0, 0.55, 0.45, 1);

Best Use Cases

• Page/view transitions
• Complex modal sequences
• Animated illustrations
• Data visualization changes
• Onboarding animations
• Feature reveals
• State machine transitions
• Loading completion celebrations

Implementation Pattern

.page-enter {
  opacity: 0;
  transform: translateX(30px);
}

.page-enter-active {
  opacity: 1;
  transform: translateX(0);
  transition: opacity 350ms ease-out,
              transform 400ms cubic-bezier(0.16, 1, 0.3, 1);
}

/* Staggered children */
.list-item {
  transition: all 400ms cubic-bezier(0.4, 0, 0.2, 1);
}
.list-item:nth-child(1) { transition-delay: 0ms; }
.list-item:nth-child(2) { transition-delay: 50ms; }
.list-item:nth-child(3) { transition-delay: 100ms; }

Key Insight

Medium duration is where animation becomes storytelling. Users watch, understand, and remember these animations. Invest in polish here - it defines perceived quality.