Spirograph

Equations: x = (R + r)·cos(t) − (r + O)·cos(((R + r)/r)·t), y = (R + r)·sin(t) − (r + O)·sin(((R + r)/r)·t)

Parameters

R – outer radius

10–300 (px)

r – inner radius

5–200 (px)

O – pen offset

0–200 (px)

Speed (Δt per frame)

Lower = slower (watch it draw!)

Canvas scale

Zoom (optional)

Stroke width

Line thickness

Max steps (safety)

Stops after this many steps

Color

Line color (defaults to site accent)

Click the canvas to pause/resume. A fading trail highlights recent motion.