No stock images, no copied artwork: every illusion here is drawn live by code, so you can change it and check it.
Drawn in code
Each illusion is a small program that draws on a canvas in your browser. Because it is code, you can move sliders, switch the trick off and see for yourself that the lines are straight or the grays are equal.
Explained with sources
Explanations are written in plain language from published research. Each page lists its references with a DOI link, checked against the Crossref database, so you can read the original papers. Where scientists still disagree, we say so.
Not medical advice
Some motion and flicker patterns can cause discomfort. If you have photosensitive epilepsy, avoid flickering illusions.