Glaze a one-of-a-kind arched window -- a true Voronoi mosaic in jewel tones, leaded and reproducible from its seed.
A Voronoi diagram divides a surface among a set of points, giving each point the region that lies closer to it than to any other -- like drawing every shop's delivery zone on a city map. The resulting cells are always straight-edged polygons, and their organic-looking mosaic appears throughout nature, from dragonfly wings and giraffe patches to cracked mud and foam. Mathematicians have studied the construction since Descartes, and it now underpins everything from cell-tower coverage maps to video-game terrain. Filled with color and outlined in dark leading, the same geometry happens to be a convincing recipe for stained glass, which is exactly how this generator uses it.
Every press glazes a new arched window: a few dozen seeded points divide the glass into panes -- a true Voronoi diagram, computed exactly -- each pane filled from a jewel palette around a seeded base hue, with the occasional pale pane for light, all held together by dark leading. No two windows repeat, and the seed on the card rebuilds any of them.
Every result here is drawn using crypto.getRandomValues() -- the Web Crypto API's cryptographically secure randomness -- instead of Math.random(), so it's genuinely unpredictable, not just statistically random. Learn more.
Palette and pattern inspiration for designers, reference for actual stained-glass and mosaic hobbyists, generative backgrounds for slides and covers -- and the copied SVG imports cleanly into vector editors, where every pane is a real polygon you can recolor.
Each press draws a 32-bit seed from the site's cryptographically secure randomness, scatters 24 to 37 points inside the window, and computes each point's pane exactly: its region is carved by clipping against the perpendicular bisector toward every other point, which is the textbook definition of a Voronoi cell. Colors come from a jewel palette built around one seeded hue -- neighbors in the same family, a few complementary accents, and roughly one pane in eight left pale, the way real windows let light through.
Real -- every pane is computed exactly as the set of points closest to its seed point, by geometric clipping rather than approximation. Copy the SVG and you'll find each pane is a precise polygon.
Yes -- pane layout and every color are determined by the seed stamped on the card.
Copy it with the SVG button in the corner and paste into any vector editor -- every pane is a separate polygon with its own fill, so recoloring is a click per pane.
Coat of Arms · Mandala · Maze · Game of Life · Langton's Ant · Fractal