About KoanKey

KoanKey is a small collection of free daily logic puzzles. Each puzzle has a single answer that you can reach by reasoning, so there is nothing to guess and nothing to look up.

The name

Say it "KOH-ahn KEE". A koan is a short puzzle that makes you stop and think. A key is what turns when you get it right. Put them together and you get the small click at the end of a good puzzle.

How the puzzles are made

Puzzles are generated by software. For each one, a solver checks that exactly one answer fits every fact, and that no fact is redundant. A fresh set goes live every day at 14:00 UTC, and past days stay online in the archive.

What is here today

Right now there is one game: Zebra puzzles, in six levels per day. More logic games are planned, and each will get its own page when it is ready.

Get in touch

A contact address will be published here before launch.