Sudoku Classic
The timeless 9×9 sudoku with a clean, uncluttered board and simple controls for desktop or mobile.

Controls
Play with the mouse on desktop or by touch on a phone or tablet: select a cell, then choose the number to place.
How to Play
This is sudoku in its purest form. Fill the 9×9 grid so that each row, each column and each of the nine 3×3 squares holds the numbers 1 to 9 with no repeats. The starting clues point the way, and the rest is steady deduction.
Should you want a refresher on the method, our step-by-step guide sets out the essentials in plain terms. After that, the tidy interface stays out of your way so you can focus on the logic.
Tips & Tricks
- Begin with the box, row or column that has the fewest empty cells.
- Cross-reference a digit down its columns and across its rows to pin its only home.
- Take your time; sudoku rewards patience far more than speed.
Frequently Asked Questions
What makes Sudoku Classic different from other versions here?
It keeps things deliberately plain, with a clean grid and no extra modes, so nothing distracts from the puzzle itself.
Does it work on a phone?
Yes. The board scales to smaller screens and responds to touch, so it plays comfortably on mobile as well as desktop.