What it does
- Draggable cubic-bezier editor with presets (Material, back, anticipate…)
- Spring simulator with stiffness, damping and mass, settle time and overshoot
- Springs exported as CSS linear() easing — no JavaScript required
- Export to CSS, design tokens, Framer Motion and SwiftUI
FAQ
Can CSS do spring animations?
Yes. The linear() easing function can approximate any curve, including a spring, by listing sampled points. The playground generates it from a real physics simulation.
How do I convert a spring to SwiftUI?
The export maps stiffness, damping and mass to SwiftUI’s .spring(response:dampingFraction:).
More free tools
- Palette Generator — Pick a hue, choose a color harmony, and get a full accessible palette with live AA/AAA contrast checking.
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- Image → Palette — Drop in an image, pull out its dominant colors, and see which pairs are safe to use together.
- Color Blindness Simulator — See a palette through protanopia, deuteranopia, tritanopia and achromatopsia — and catch colors that collapse.
- Type Scale Generator — Pick a base size and a ratio, get a full type scale with live preview, fluid clamp() and tokens to copy.
- Gradient & Mesh Generator — Linear, radial, conic or blobby mesh gradients — drag the points, shuffle the colors, copy the CSS.
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- Design Token Converter — Paste W3C tokens, Tokens Studio or Figma Variables JSON and get CSS, SCSS, Tailwind v4 or SwiftUI — aliases included.
- Auto-Trim — Drop in PNGs and get them back without the empty transparent edges — in bulk, in your browser, as one ZIP.
- Text Expansion Stress Test — See how a UI breaks in German, Spanish or pseudo-localized text — and which CSS fixes make it survive translation.
- Mini A11y Audit — Paste HTML and find missing alt text and labels, unnamed buttons, heading jumps, tiny tap targets and low contrast.
- Multi-size Preview — One message laid out across social and display-ad sizes, with platform safe zones and a draggable focal point. Export every PNG.