About Puzzdoku

Puzzdoku is a small, independent site for Sudoku-style logic puzzles you can play in a browser in seconds.

What we make

The name says it: puzzle + doku, the "single" in Sudoku. We focus on grid puzzles where every row, column and region follows one simple rule: Cat Sudoku, classic Sudoku and Kakuro, plus a daily puzzle habit to go with them.

How our puzzles are made and checked

• Unique solutions, always. Every board is run through an exhaustive solver that counts solutions. Anything with more than one answer is thrown away.
• Logic, not luck. Cat Sudoku boards are also solved by a second solver that only uses human techniques (single cells, locked regions, touch eliminations and region groups). If it can't finish without guessing, the board isn't published.
• Honest difficulty. Cat Sudoku and Sudoku are rated using a human-technique solver. Kakuro levels are grouped by grid size, from small beginner boards to larger challenges.
• Hints that teach. Hints explain a logical step when one is available. If the built-in techniques cannot find one, Sudoku and Kakuro clearly label any revealed digit.

Our principles

• No account, no download, no paywall.
• Your progress stays in your browser. We don't build profiles of players.
• Fast pages that work on old phones and slow connections.

Get in touch

Found a bug, have an idea for a puzzle, or want to say hi? Email hello@puzzdoku.com or visit the contact page.