Graph Builder

This graph

Colouring check

Vertex and edge sets

Type the edge set, e.g. E = {(a,b), (a,c), (b,c)}. Repeat a pair for multiple edges and use (c,c) for a loop. Add V = {a, b, c, d} to include isolated vertices.

Options

Show degrees on the drawing New vertices are labelled

How to use

Build: This can be done in different ways. 1) Click an empty space to add a vertex. To add an edge, click one vertex, then another, to join them with an edge. Click the same vertex twice to add a loop. 2) Type out a vertex set and edge set in the box above. This must be done in set notation.
Drag a vertex to move it. Drag an edge to bend it. This works in every mode.
Click a label to rename the vertex.
Colour: pick a colour, then click vertices or edges. The crossed-out colour removes a colour.
Delete: click a vertex or edge. Deleting a vertex deletes its edges too.
Scramble and Circle redraw the same graph with the vertices in new places. Nothing in the side panel changes.
Shortcuts: B C D switch modes, 1–8 pick a colour, 0 no colour, Esc cancels an edge, Ctrl/⌘ Z undoes.