Guess the Size is a free browser game about how big things really are. Each round shows something familiar at its real size next to a mystery object – stretch the mystery object until you think it matches, lock it in, and see how close you got. From an ant to the Sun, with sizes taken from encyclopedias and NASA. Play a new 5-round puzzle every day and share your score, chase a high score in unlimited mode, or duel Sizebot. No sign-up, works on your phone.