CSS Animation Timeline Editor - Visual Keyframe Animation Creator

Free online CSS animation timeline editor for visual keyframe creation. Multi-track editing, real-time preview, bezier curve control, one-click CSS export.

What is a CSS Animation Timeline?

A CSS animation timeline is a visual interface for creating and editing keyframe animations. Instead of manually writing CSS code, you can drag keyframes on a timeline, adjust properties visually, and see the animation play in real-time.

Timeline editors are similar to video editing software or animation tools like After Effects, but specifically designed for CSS animations. They make it easy to create complex multi-element animations without deep CSS knowledge.

How CSS Keyframe Animations Work

CSS animations use the @keyframes rule to define animation steps:

@keyframes fadeIn {
  0% {
    opacity: 0;
    transform: translateY(20px);
  }
  100% {
    opacity: 1;
    transform: translateY(0);
  }
}

.element {
  animation: fadeIn 1s ease-out;
}

The animation property combines duration (1s), timing function (ease-out), and other options. You can also specify delay, iteration count, direction, and fill mode.

Features of Our Timeline Editor

  • Multi-Track Editing: Create animations for multiple elements on separate tracks
  • Visual Keyframe Editor: Drag keyframes on the timeline to adjust timing
  • Real-Time Preview: See your animation play instantly as you edit
  • Bezier Curve Control: Fine-tune easing with custom cubic-bezier curves
  • Property Animation: Animate any CSS property (transform, opacity, color, etc.)
  • One-Click Export: Generate clean CSS code ready to copy and paste
  • No Signup Required: 100% free, runs in your browser

CSS Easing Functions

Easing functions control the speed curve of animations. Common options include:

  • linear: Constant speed throughout the animation
  • ease: Default timing function, slow start, fast middle, slow end
  • ease-in: Slow start, accelerating to full speed
  • ease-out: Fast start, decelerating to stop
  • ease-in-out: Slow start and end, fast middle
  • cubic-bezier(x1, y1, x2, y2): Custom bezier curve for precise control

Our timeline editor includes a visual bezier curve editor, making it easy to create custom easing functions by dragging control points.

Animatable CSS Properties

Most CSS properties can be animated, including:

  • Transform: rotate, scale, translate, skew
  • Opacity: Fade in/out effects
  • Colors: background-color, color, border-color
  • Dimensions: width, height, margin, padding
  • Position: top, right, bottom, left
  • Box Shadow: Animate shadow properties
  • Border Radius: Morph shapes

Some properties like display cannot be animated. Check MDN's list of animatable properties for the complete reference.

How to Use the Timeline Editor

  1. Add a Track: Click "Add Track" to create a new animation track
  2. Set Duration: Adjust the track duration (e.g., 1000ms)
  3. Add Keyframes: Click on the timeline to add keyframes at specific times
  4. Edit Properties: Select a keyframe and modify CSS properties
  5. Adjust Easing: Choose an easing function or create a custom bezier curve
  6. Preview: Click "Play" to see your animation in action
  7. Export: Click "Export CSS" to get the generated code

Performance Tips

  • Use transform and opacity: These properties are GPU-accelerated and perform best
  • Avoid animating layout properties: width, height, margin, padding trigger reflows
  • Use will-change: Hint to the browser which properties will animate
  • Limit simultaneous animations: Too many animations can cause jank
  • Test on mobile: Mobile devices have less processing power

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