Guess the size
The daily five
Five comparisons, the same for everyone. Resize each target, trust your eye, and see how close you can get to 500. A new set arrives at 00:00 UTC.
The world is waiting.
Preparing your size challenge…
A better eye for real-world scale
The green reference has a known size. Adjust the coral target with the slider, buttons or sideways dragging. Read the height, length or diameter labels before locking in.