Cellular automata guide

Start

The tool opens with the Game of Life on a grid already filled at random, paused at generation 0.

What you need

• A current browser with JavaScript on. Chrome, Edge, Firefox and Safari all work.
• Nothing else. There is no picture to bring; you draw the cells.

Your first result

1. Open Cellular automata. A random grid is waiting.
2. Pick a rule under Rules. For your own, press Custom and type a rule such as B3/S23 in the Custom rule box that appears.
3. Drag on the grid to paint cells, or pick a shape under Patterns and tap the grid to place it.
4. Press Play. Generations / sec sets the speed, and Pause stops it. Step moves one generation at a time.
5. Scroll or pinch to zoom. Press Save PNG at the top of the panel to keep the picture.

Good to know

• A rule string reads B, then the neighbour counts that make an empty cell come alive, then S and the counts that keep a live cell alive. B36/S23 is born with 3 or 6 and survives with 2 or 3. B2/S has no survive counts, so every live cell dies after one step.
• To move the grid with a mouse, drag with the middle button, or hold Space and drag. On a touch screen, drag with two fingers.
• A pattern stays picked, so each tap places another. Pick a tool under Drawing to go back to painting.
• The counters over the grid show the generation, the number of live cells (Pop) and how many generations ran in the last second.
• On a phone the controls sit in a bar at the bottom of the screen. Tap the bar to open them.