Sudoku
Fill the 9×9 grid so every row, column and box contains 1 to 9.
How to use: Tap a square, then tap a number. Every row, column and 3×3 box needs the digits 1 to 9 once.
How to play Sudoku
Sudoku is a logic puzzle. The goal is to fill a nine-by-nine grid with the digits 1 to 9 so that each row, each column and each of the nine three-by-three boxes contains every digit exactly once. No arithmetic is needed; it is purely about deduction.
Pick a difficulty and a new puzzle is generated instantly in your browser. Every puzzle is built to have exactly one solution, so you never need to guess. Click a cell and then a number on the pad, or type the digit on your keyboard; use the arrow keys to move. Conflicting numbers are highlighted in red as you go. The hint button fills the selected cell, and the check button tells you whether any entries are wrong.
Start by scanning for digits that appear often and look for the one cell in a row, column or box where a number can still fit. When that fails, write down the candidates for a cell in your head and eliminate them using the numbers around it. Harder puzzles need patterns such as pairs, where two cells share the same two possible digits and so rule those digits out of the rest of their group.
A timer runs while you play so you can track your progress. Easy puzzles reveal about 40 numbers, medium 32 and hard 26. Take your time: accuracy matters more than speed.
Frequently asked questions
Does every puzzle have a unique solution?
Yes. Each puzzle is checked to confirm that exactly one solution exists.
Can I get a hint?
Yes. Select an empty cell and press Hint to fill it with the correct digit.
How do I enter numbers?
Click a cell, then press a number on the pad or your keyboard. Backspace or the eraser key clears it.