Cellular automata guide

Help

Short answers to what goes wrong most often.

The grid stays blank

The tool needs JavaScript. It draws on a 2D canvas and needs no WebGL. Reload the page, and if the grid is only empty, press Random fill.

It is slow

A grid of 500 cells a side has 250,000 cells to count every generation. Lower Cells per side and press Apply size, or lower Generations / sec. The Gen/s counter shows how many actually run.

Everything died, or nothing moves

Many rules end in empty space or still shapes. Press Random fill for a new start, place a Gosper gun, or try another rule. Rule 110 and Langton's ant need Play to show anything new.

My custom rule does nothing

Check that Custom is picked and the text reads like B36/S23: B, digits from 0 to 8, then S and digits. Text that does not fit is ignored, and the last good rule stays.

Grid lines does nothing

Lines show only when each cell is at least 4 pixels wide. Zoom in, or use a smaller grid.

Tapping keeps placing a pattern

A pattern stays picked until you pick a tool. Press Paint under Drawing to draw again.

In WireWorld I cannot start a signal

Paint, Line and Rectangle lay wire. Cells placed by a pattern, and cells from Random fill, start as electron heads, so place a small pattern on your wire to start one.

Does it work on a phone or tablet?

Yes. Drag with one finger to draw. Put a second finger down to pinch and move the grid; the cell your first finger just painted is taken back. Phones open with a grid of 100 cells a side and stop at 250.

Copy did nothing

Some browsers do not let a page write to the clipboard. Use Save PNG for the picture.

Is anything uploaded?

No. The grid lives on your device and never leaves it.