Loading…

Resize the silhouette · lock it in · red reveals the true size — 5 rounds a day, free, no account

The idea

It starts with a question you can't quite answer

You can recognize a blue whale, a giraffe or the Eiffel Tower in a second — but almost nobody can say how big they actually are. Recognizing something and knowing its size are two different skills; the gap between them is where this game starts.

In September 2026 a browser-game team known for daily puzzles turned it into a real format: every day, players around the world get the same size comparisons, drawn as silhouettes instead of photos — handing the sense of scale back to each player's own eyes. This site is an independent re-implementation of that format: the rules are public, the data traceable, and the silhouette library and scoring are our own.

It belongs to the daily-puzzle lineage. Since Wordle made “the same puzzle for everyone, one per day” the default of browser games in 2021, the idea has spread — Worldle for country outlines, GeoGuessr for places, Higher or Lower for prices. Size It Up swaps “guess the name” for “guess the scale”: you don't need to know how many floors 27 metres is, you just need to make two silhouettes look right.

How to play

Three steps to a scale expert

No numbers, no typing — just make the two silhouettes look right. Your eyes are better at sizes than you think.

01

Compare the reference

The black silhouette on the left is drawn at its true size, with a scale line marking its length or height. Everything is judged against it.

02

Stretch your target

Drag and resize the white silhouette until the proportion feels right. Way off? Zoom out and start again.

03

Lock it in, watch the red reveal

Hit lock, and the true size snaps into place as a red outline over your guess — with your error percentage and a fact worth remembering.

≤6% off → 100 pts · ≤12% → 90 · ≤20% → 78 · ≤33% → 62 · 2× / half → 45 · 3× → 30 · ≥5× → 0 · Daily max 500

Each round compares a single dimension — length, height or diameter — marked by the measurement line on the board. A giraffe is compared by height, a blue whale by length; when a long silhouette and a tall one sit side by side, don't let the overall look fool you — you're answering the question the line asks.

Three habits make the next round more fun: guess the ratio before the numbers — is it half the reference, twice it, or ten times? Watch the measurement line, and move the target if the composition tricks you. After locking, spend five seconds on the red overlay and remember one specific correction — knowing how you were wrong beats knowing that you were.

The library

A silhouette library, every size sourced

Each round pairs two silhouettes: one is the reference, the other the target — the same object can play either role on different days.

The library currently ships with 8 verified silhouettes — blue whale, giraffe, T. rex, saltwater crocodile, Eiffel Tower, Statue of Liberty, bicycle and human — and keeps growing. Every size is an approximate adult or standard dimension taken from published data (encyclopedia entries, official spec sheets); the silhouettes are openly licensed artwork from Wikimedia Commons, credited in-game.

A size describes one specific individual or definition — an adult giraffe, the Eiffel Tower with its antenna. That's why the one-line context on each answer is part of the answer itself: 27 m is a blue whale, not a bus.

Modes · all free

Four ways to play

All free, no account — the browser is the whole game.

DailyLive

Every player on Earth gets the same five rounds today; a fresh set starts at your local midnight. Come back daily to grow your streak.

Play today's puzzle →

UnlimitedComing soon

No daily cap. Random pairs from the whole library — animals, dinosaurs, vehicles, buildings, planets… practice as long as you like.

AnimalsComing soon

Only the animal kingdom: blue whale, giraffe, T. rex, saltwater crocodile… Photos lie, silhouettes don't.

GeographyComing soon

Countries, US states and lakes as silhouettes: is Japan longer than New Zealand? Is Texas bigger than France?

The daily ritual

Five minutes a day, comparing eyes with the world

Daily mode is a fixed 5 rounds, max 500 points. Finish all five to keep your streak alive; miss a day and it restarts at one.

Progress and streaks live in your browser's local storage: switching browsers or clearing site data resets your history. Staying in one browser is the only way to keep a streak.

Puzzles come from a deterministic seed of date + library, so refreshing the page changes nothing — only a new day brings a new set. Today's set belongs to today.

Sizes that surprise

Pairs almost everyone gets wrong

You know these objects — but you've rarely stood next to one. Bars are drawn to true scale.

Bicycle1.75 m
Blue whale27 m
15.4×Blue whale / bicycle
Human1.75 m
Giraffe5.5 m
3.1×Giraffe / human
Statue of Liberty93 m
Eiffel Tower330 m
3.5×Eiffel / Statue of Liberty
Bicycle1.75 m
T. rex12 m
6.9×T. rex / bicycle
Share

Send the card, start a friendly fight

Finish a set and you get a color-block result card: green close, yellow off, red wild — five blocks that read your eye at a glance without spoiling a single answer.

SIZE ITUPDAILY
12345
420/500

sizeitup.co

Send the card to a friend, then share the link: you both play the same set blind, and only when the answers land do you find out whose eyes are better.

Sample card — yours is generated automatically after each set.

FAQ

Questions, answered

How do I play?+
Each round shows a black reference silhouette at its true size — for example a 1.75 m person. A white silhouette is your target: resize it to what you think the target's real size is, then lock in. The true size is revealed in red with your error and score.
How is the score calculated?+
The closer your guess, the more points: within 6% scores 100, within 12% scores 90, one-fifth off scores 78, one-third off scores 62, half or double scores 45, three times off scores 30, and five times off or worse scores 0. Five rounds per day, max 500.
Why one set per day?+
Every player gets the same five puzzles each day, so you can compare results and challenge friends. A new set starts at your local midnight.
Do I need the exact size for 100 points?+
No. Within 6% — guessing 5.3 m when the answer is 5 m, say — is a 100. Full marks reward close enough, not landing the thumb on one exact decimal.
Why silhouettes instead of photos?+
Lenses lie. An animal filling the whole frame can be far smaller than one always shot from far away; photos bring perspective, depth and background cues that distort your judgment. Silhouettes strip all of that away — which is exactly why this game uses them.
Where do the silhouettes and measurements come from?+
Silhouettes are openly licensed artwork from Wikimedia Commons (CC0 / CC BY / CC BY-SA), credited in-game. Sizes are approximate adult measurements sourced from Wikipedia.
Do I need an account?+
No. Everything — progress, streak, results — is stored locally in your browser.
Does it work on mobile and tablet?+
Yes. On touch screens you drag the target, drag the slider or pinch to resize, and use the corner handle for fine adjustments; the board adapts to any screen width. No app to install.
Is it really free?+
Yes. The daily game is free to play with no ads.