Size Duel
Daily duels, ten a day
120 things from a red blood cell to the Sun: lengths, heights, mountain heights and masses.
No streak yetPractise by category
Two things.Pick the bigger one.
Then see them side by side, drawn to the same scale, with a person for comparison and a note on why it surprises people. Ten duels a day, every answer checked against two sources.
Two decks, one duel
Both decks use the same rules: one named measure, a clear gap, two sources. Your streak for each deck is kept separately.
Older Than
Daily duels, ten a day
150 inventions, buildings, books, places and events. Which came first?
No streak yetPractise by category
How a duel works
One question, one measure
“Which is taller?” compares heights only; a giraffe never meets a lorry on weight. Tap a card, or press 1 or 2.
See it to scale
Both things appear at their true size next to each other, with a person, a bank card or a scale bar for comparison. Dates go on a short time ruler.
Learn the surprise
A one-line note says why the answer catches people out. Every item has its own page with both sources quoted.
Questions
Size Duel is a small, honest game: no account, no ads, every fact sourced.
What is Size Duel?
A free two-choice game about the real world. Two things appear: pick the longer, taller, higher or heavier one. Then both are drawn to the same scale next to a person or a bank card, with a short note on why the answer surprises people.
What is Older Than?
The second deck on this site: two inventions, buildings, books, events or places. Pick the one that came first, then see both on a short time ruler with the gap in years.
Is it fair?
Every duel compares one named measure, like height with height, never height with weight. Two values must differ by at least 15% (dates: by at least two years) and their ranges must not overlap, so natural variation never decides the answer. Each value was checked against two sources, listed on its page.
How does the daily work?
Each deck has ten duels a day, the same for everyone, changing at midnight UTC. Finish on the day to grow your streak; a round you start before midnight still counts if you finish within two hours after. Past days are in the archive and never change your streak.
What is the endless streak?
Duel after duel until your first miss. It never repeats an item until it has shown the whole deck, and it gets harder as you go.
Can I play it on stream?
Yes. Streamer mode makes the type bigger, keeps the bottom-right corner free for a webcam, mutes sounds by default and adds a “chat, vote now” countdown before you can answer. It has no chat connection: chat votes in your chat, you click.
Does it work offline?
Yes. After your first visit both decks and every drawing are kept on your device.