SizeGuess starts with a simple question: you know what something looks like, but do you know how big it really is? A familiar silhouette beside a known reference makes that gap visible.
Play first. Learn something along the way.
Each round asks you to judge a real-world dimension. The reveal supplies a measurement, a source note and another reference you can carry into the next comparison. The daily five makes a short ritual; Unlimited and category practice let you keep exploring.
Our own perspective
SizeGuess is independently developed. It takes inspiration from the visual resizing mechanic popularised by Size It Up and from the wider tradition of daily browser puzzles. Our brand, interface, illustrations, curated catalogue, scoring formula and code are our own. SizeGuess is not affiliated with Size It Up or other game publishers.
Clear measurements matter
A whale’s length, a tower’s height and a planet’s diameter are different dimensions. We label the chosen axis and convention, link to the measurement source and treat natural variation and reconstructed dimensions as part of the context.
No account required
The game runs in your browser. Personal results are saved locally, and the daily set is generated automatically. The comparison tool and measurement library are free to explore.
Read the methodology or send a correction or suggestion.