About Daily Sudoku

Our Story

Daily Sudoku began as a hobby in 2005. What started with solving puzzles on paper turned into analyzing them, then building software to generate them. Two decades later, that software publishes a fresh set of puzzles here every day.

Along the way we have generated thousands of grids and published several printed Sudoku books. This site is the continuation of that work: one carefully tested puzzle per difficulty, every day, free.

Our Mission

At Daily Sudoku, our goal is simple: to provide a clean, elegant, and accessible platform for everyone to enjoy their daily mental workout. Whether you are a beginner learning the ropes or a seasoned master tackling our hardest levels, we are thrilled to have you as part of our community.

How Our Puzzles Are Made

Every grid is produced by our own generator and verified twice before publication. A solver first proves the puzzle has exactly one solution. A grader then solves it using only human techniques, from naked singles to X-Wings, to confirm its difficulty rating. No published puzzle ever requires guessing.

The same pipeline produces the daily puzzles, the printable PDFs, and our Killer Sudoku cages. If a grid fails any check, it is discarded.

About the Author

Our puzzles are published under the pen name Kenjiro Sato, a nod to Sudoku's Japanese publishing tradition. Behind the name is a real puzzle maker who has been building and refining our generator since 2005 and is the author of our printed puzzle books.

Found a bug, spotted an error, or have an idea? Contact us.