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Color Blindness Simulator

Preview a color palette as people with protanopia, deuteranopia, tritanopia and achromatopsia see it, and catch colors that become indistinguishable.

What it does

  • Simulations based on Machado et al. (2009), with adjustable severity
  • Flags color pairs that collapse into each other for each vision type
  • Preview the palette in a chart and status pills, not just swatches
  • Shareable palettes through the URL

FAQ

How common is color blindness?

About 1 in 12 men and 1 in 200 women have some form of color vision deficiency; red-green types (protan and deutan) are the most common.

How do I fix colors that collapse?

Don’t rely on hue alone: vary lightness between colors and add labels, icons or patterns, as WCAG 1.4.1 (Use of Color) requires.

More free tools

  • Palette Generator — Pick a hue, choose a color harmony, and get a full accessible palette with live AA/AAA contrast checking.
  • Contrast Checker — Paste two colors, see the WCAG ratio, and fix a failing pair with a single click.
  • Image → Palette — Drop in an image, pull out its dominant colors, and see which pairs are safe to use together.
  • 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.
  • Component States Explorer — Buttons, inputs and cards in every state — hover, focus, pressed, disabled, error — side by side with contrast checks.
  • Design Token Converter — Paste W3C tokens, Tokens Studio or Figma Variables JSON and get CSS, SCSS, Tailwind v4 or SwiftUI — aliases included.
  • Motion & Easing Playground — Drag cubic-bezier handles, tune a real spring, watch them race, and export motion tokens as CSS linear(), Framer Motion or SwiftUI.
  • 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.