How to use the Voronoi generator
- Click the canvas to place sites, or press Random to scatter as many as you set on the slider.
- Drag a site to move it; the cells update live. Right-click or double-tap a site to remove it.
- Press Relax a few times to even out the cells (Lloyd's algorithm). Ten steps gives a calm, honeycomb-like pattern.
- Choose a palette, border width and background. Neighboring cells never share a color, except in Mono.
- Turn on the Delaunay triangulation or the cell centroids to see the geometry behind the diagram.
Your sites are kept in this browser, so the diagram is still here when you come back.
What you are looking at
Each colored region is a Voronoi cell: every location inside it is closer to its own site than to any other. Borders run exactly halfway between neighboring sites, along their perpendicular bisectors, and three borders meet at points that are equally far from three sites. Because the cells cover the canvas with no gaps or overlaps, the result is also called a Voronoi tessellation — or, in geography, Thiessen polygons.
The faint triangles you can switch on are the Delaunay triangulation, the diagram's dual: two sites are joined whenever their cells share a border. Learn more in What is a Voronoi diagram?, or put your sites on real places with the Voronoi map generator.
Frequently asked questions
What is a Voronoi diagram?
A Voronoi diagram splits a plane into cells around a set of points (sites). Every location inside a cell is closer to that cell's site than to any other site.
Is a Voronoi tessellation the same as a Voronoi diagram?
Yes. Tessellation means the cells cover the plane with no gaps or overlaps, which is exactly what a Voronoi diagram does. Other names are Dirichlet tessellation and, in geography, Thiessen polygons.
What does Relax do?
Relax runs one step of Lloyd's algorithm: each site moves to the centroid of its cell. Repeating it makes the cells more even in size, which is useful for patterns and procedural maps.
Why do cells at the edge look larger?
Edge cells have no neighbor on one side, so they extend to the frame. Add sites near the border or relax the diagram to balance them.
Is my data sent anywhere?
No. The diagram is computed in your browser and your points are only kept in this browser.