Resume or explore your JND session

Upload the JSON file from a previous run to pick up the adaptive staircases where you left off or explore your psychometric functions without running a new experiment.

No previous session loaded.

Calibrate your display

Pick a familiar object, hold it gently against the screen, and resize the on-screen shape so it matches. This lets us convert every pixel on your display into degrees of visual angle.

Keep the screen at the same distance from your eyes throughout the experiment. If you move, stop and recalibrate before continuing.

Pinch to zoom or use the slider
cm

Calibration required before the experiment can begin.