Hypno Spiral

The hypnotic spiral is one of the best-known optical illusions: a rotating spiral seems to pull you in or push outward, and after watching it for a while, still objects can appear to move – the motion aftereffect. This spiral maker draws the pattern live in your browser. Change the number of arms, the twist, the speed, the direction and both colours, add a word in the middle, and use it as a screen visual, a video background, a stage or party effect, or simply to experiment with the illusion. Share links store all settings in the URL, nothing is uploaded.

A rotating spiral stimulates the motion-detecting cells in your visual system in one direction for a long time. When you then look at something still, those cells are 'tired' and the opposite cells win for a moment, so the still image seems to expand or shrink. This motion aftereffect is a well-studied illusion and works with almost any steadily moving pattern. Spirals became the symbol of stage and film hypnosis because they show the effect so strongly, but watching a spiral does not hypnotise anyone on its own.

Use full screen on a TV or projector as a party, Halloween or stage visual; screen-record it for a video background or a meme; try different colour pairs for a retro or psychedelic look; or put a word in the centre for a title card. Slow speeds with few arms look calm, many arms and high speeds look intense. Double-click the spiral to switch to full screen quickly.

The spiral does not flash, but strong moving patterns can cause dizziness, eye strain or nausea for some people. Lower the speed, take breaks, and stop if you feel unwell. If your device is set to reduce motion, the spiral stays still.