Blog
The Zeloku blog
One topic per post, sourced and fact-checked — the history, the maths and the stories behind the puzzle. For rules and technique guides, see Learn instead.
Maths
How Many Sudoku Puzzles Are There?
The exact count is 6,670,903,752,021,072,936,960 grids. Here's who calculated it, what it actually means, and why the puzzle will never run dry.
2026-07-27 · 7 min read
Records
Sudoku World Records: Who's Actually the Fastest?
The real Guinness World Record (2:08.53, set in 2006), the WSC's most decorated players, and who won in 2025 — with sources.
2026-07-26 · 9 min read
Origins
The History of Sudoku
Who really invented Sudoku, and why is it called that? The real timeline — 1979 America, 1984 Japan, 2004 London — to today.
2026-07-26 · 8 min read
Or just play Sudoku
- Play Sudoku
- Online Sudoku
- Sudoku puzzles
- Sudoku game
- Daily Sudoku
- Classic Sudoku
- Easy
- Medium
- Hard
- Expert
- Evil
- Extreme
- Mini Sudoku
- Kids Sudoku
- Beginner
- Solver
- Printable
- Sudoku PDF
- What is Sudoku?
- How to solve
- Strategies
- Techniques
- Variants
- Unlimited
- No ads
- App
- Tips & tricks
- Get better
- Learn
- History of Sudoku
- Sudoku world records
- All pages