About FreeMathDoku

Last updated 2026-10-10

FreeMathDoku is a free set of browser tools for calcudoku, the grid puzzle also known as mathdoku or KenKen: play puzzles online, print sheets with answers, generate your own and solve a puzzle you are stuck on. Each page does one job and works straight away: there is no account and nothing to install.

How it works

• Everything runs in your browser. What you type or choose stays on your device; nothing is uploaded.
• Results are computed, not typed in. The examples on each page are produced by the same code the tool runs, and the code is tested against independently calculated results.
• Third-party material used on the site is listed on the credits page.

If a tool gives a wrong result, please tell us through the contact page.

Names and trademarks

KenKen® is a registered trademark of Nextoy, LLC. FreeMathDoku is not affiliated with or endorsed by Nextoy; we use the name only to describe the type of puzzle. Our puzzles are generated by our own code.

Who runs it

FreeMathDoku is owned and operated by SKYSEED TECH LLC. You can write to us at jun@freemathdoku.com.

Advertising

The site is free to use. We may show advertising in future to pay for hosting and development. If we do, ads will be labelled “Advertisement”, will never cover a tool, and are described in the privacy policy.