Fill every row, column, and 3×3 box with the numbers 1 through 9 — no number repeating anywhere in the same row, column, or box. Despite the numbers, it's pure logic, not math. Every puzzle below is free to play right in your browser, or print it the old-fashioned way with the answer key folded on the back.
Easy · Hard — a medium tier is on the way as the library grows
Plenty of givens and no advanced techniques required — straightforward scanning carries you to a finished grid.
Print this puzzle » See all easy sudoku »The leanest grid in the library. Expect pairs and elimination to carry real weight before the rest opens up.
Print this puzzle » See all hard sudoku »Sudoku fills a 9×9 grid with the numbers 1 through 9, so that every row, every column, and every 3×3 box contains each number exactly once. Despite the numbers on the grid, there's no arithmetic involved — it's pure logic, working out what has to go where by process of elimination.
Start by scanning for near-complete rows, columns, and boxes — the fewer empty cells left, the fewer possibilities remain, and often only one number fits. Sweep the grid this way first before reaching for anything more advanced; on our easy puzzles, that alone is usually enough to finish.
On the harder grids, simple scanning eventually runs dry. That's when pencil marks earn their keep: lightly note every number still possible in a cell, then look for cells where only one candidate remains. Watch too for pairs — two cells in the same row, column, or box that can only hold the same two numbers between them, which lets you rule those numbers out everywhere else in that row, column, or box.
Want the full method, step by step? Read our complete guide to solving sudoku.
If a puzzle has you stuck, our free sudoku solver can check your work or fill in the rest instantly — type in what you have and let it take it from there.