Sudoku — How to Play & Solve Faster
Goal: fill the 9×9 grid so every row, every column, and every 3×3 box contains the digits 1–9 exactly once. You start from a partially filled grid; nothing needs guessing — every proper sudoku is solvable by logic.
Three solving techniques, in the order to learn them
- Scanning: pick a digit, scan its rows and columns to eliminate cells, and place it where only one box-cell remains.
- Naked singles: when a cell's row+column+box rule out eight digits, the ninth goes in.
- Candidate pairs: if two cells in a row can only be the same two digits, those digits are locked there — eliminate them from the rest of the row.
FAQ
How long should an easy sudoku take?
Beginners: 10–20 minutes; practiced solvers finish easy grids in 3–6 minutes using scanning alone.
Is guessing ever required?
No. Every published puzzle on this site is logic-solvable; if you are guessing, a deduction was missed.
What makes a puzzle hard?
Fewer starting clues and the need for advanced techniques like pairs, triples, or box-line elimination.
Want the full system? Read our complete sudoku strategy guide.