SizeItUp (also written "Size It Up") is a free browser-based daily game that tests your sense of scale: each round shows a familiar teal object drawn at real size, and you stretch an orange shape until it looks right beside it.
What is SizeItUp?
SizeItUp is a daily size comparison puzzle played in the browser at sizeitup.us. Every round renders a reference object at its true scale, you resize a second object by dragging, pinching or using the arrow keys, then confirm to see the true outline overlaid on your guess along with the real measurement and its source. It runs on web with no install and no account required, and ships in English, Spanish, Portuguese (Brazil), French, German and Japanese.
What makes SizeItUp stand out?
- Sourced answers — every reveal names what is being measured and links to the source: ISO standards and sports rulebooks for everyday objects, NASA fact sheets for space, museum specimens and published papers for extinct animals.
- Three daily puzzles — Classic (everyday things, from a credit card to the Burj Khalifa), Cosmic Scale (planets, moons, stars and spacecraft, measured by NASA) and Prehistoric Giants (dinosaurs and extinct animals beside living ones). Each has its own leaderboard.
- Ratio-based scoring — up to 100 points per round and 500 per day; because scoring uses the ratio between guess and truth, guessing double is as far off as guessing half.
- Midnight reset in your timezone — a new numbered puzzle per game each day, with an archive that replays any past day.
- Free play mode — unlimited rounds dealt from the full collection of every game, outside the daily limit.
- Insight currency — signed-in players earn a points balance spendable in the shop on titles and board themes.
- Size reference library — the "How big is it?" page lists every object with its size and source.
- Six languages — English, Spanish, Portuguese (Brazil), French, German and Japanese.
Who should use SizeItUp?
- Daily-puzzle regulars — people who already play a word or number game each morning and want a five-round scale quiz that takes a couple of minutes.
- Curious science readers — players who want to check whether a fact about Saturn's diameter or a mammoth's shoulder height holds up, with the NASA or museum citation attached.
- Teachers and parents — an object-size warm-up where the reveal shows a real number and where it came from, rather than just a right/wrong verdict.
What can you do with SizeItUp?
- Casual commuters: finish the five Classic rounds on a phone in a few minutes and compare your daily score on the leaderboard.
- Space enthusiasts: work through Cosmic Scale rounds sized against NASA fact sheets, then check the numbers in the sizes library.
- Trivia and quiz players: use free play to drill endless rounds from every collection and improve at judging ratios.
- Returning players: replay missed days from the archive instead of losing the puzzle.
How does SizeItUp work?
Each round follows four steps. First, read the teal object, which is drawn at its real size and acts as your ruler. Second, stretch the orange shape by pulling, pinching or using the arrow keys until it looks correct beside the reference. Third, confirm so the true outline lands over your guess with the real number and its source. Fourth, score — within 6% earns the full 100 points, twice or half the size scores about 33, and five times off scores nothing.
Pricing
SizeItUp is free. There is nothing to buy with money, no purchase affects your score, and the shop spends Insight points rather than currency.
FAQ
Do I need an account to play SizeItUp?
No — anyone can play as a guest. Signing in with Google adds the daily leaderboard, your streak synced across devices, and Insight, a points balance you can spend in the shop on titles and board themes.
Can I play more than five rounds a day?
Yes. Free play deals unlimited rounds from each game's whole collection. Free play and archive replays do not count toward streaks, leaderboards or Insight.
How is each round scored?
Up to 100 points per round and 500 a day, based on the ratio between your guess and the true size. Landing within 6% scores all 100 points; guessing twice or half the real size scores about 33; being five times off scores nothing.
When does a new SizeItUp puzzle appear?
A new numbered puzzle for each game appears at midnight in your timezone. If you miss a day, the archive lets you replay any past daily puzzle.
Are the sizes verified?
Every answer names what is measured and links to its source, using ISO standards and sports rulebooks for everyday objects, NASA fact sheets for space, and museum specimens and published papers for extinct animals. All objects are listed with size and source on the sizes page.
