Guess the size

Same five. Different eyes.

Create a challenge link and send it to a friend. Both of you receive the same five comparisons, with the same scoring and no account required.

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.

Get a sense of scale.

  1. Find your reference.The object on the left has a known measurement. Check the height, length or diameter label.
  2. Resize your guess.Pull the corner of the coral silhouette, use the slider, or tap − / +. The green reference stays fixed. Fit view changes only the camera.
  3. Lock it in.The teal silhouette animates to its true size; your coral guess stays visible for comparison. Earn up to 100 points per round; five rounds make 500.

Your perspective.

Play a set to start your personal history.

Share a perspective.

Same silhouettes. Same rounds. Who has the better eye?

Open WhatsApp ↗

Clear your progress?

This removes SizeGuess scores, saved rounds and streaks from this browser.