Pick a cell, then a number. Fill every row, column, and box with 1–9.
Tip: turn on Notes to pencil in candidates, and tap a filled number to highlight all of its matches.
How to play Sudoku online
The original: Number Place by Howard Garns, first printed by Dell Magazines in 1979. Japan’s Nikoli named it Sudoku in 1984. Ours is an independent version, not affiliated with either.
Sudoku is the classic logic number puzzle: a 9×9 grid you fill so that every row, every column, and every 3×3 box contains the digits 1 through 9 exactly once. No math required — just deduction. This free browser version has four difficulty levels from Easy to Expert, plus pencil notes, with no downloads or signup.
Sudoku rules
The grid. Nine rows, nine columns, and nine 3×3 boxes. Some cells start filled — those are your clues.
The one rule. Each digit 1–9 appears exactly once in every row, once in every column, and once in every 3×3 box.
Solved. The puzzle is done when every cell is filled without breaking that rule. A proper Sudoku has exactly one solution.
Sudoku tips & strategy
Scan for singles. Find a cell where only one digit can legally go — the most reliable way to make safe progress.
Hunt the hidden single. Within a row, column, or box, look for a digit that fits only one cell.
Use pencil notes. Jot the candidates for tricky cells; eliminating candidates is where harder puzzles are cracked.
Work the busy areas. Rows, columns, and boxes that are nearly full give the most clues — start where the constraints are tightest.
Never guess on a proper puzzle. Every Easy-to-Expert grid here is solvable by pure logic; if you're stuck, there's a deduction you haven't spotted yet.
Frequently asked
How do I play Sudoku? Fill the empty cells with digits 1–9 so that no digit repeats in any row, column, or 3×3 box. Use the starting clues to deduce the rest — one cell at a time.
Is Sudoku math? No — the numbers are just symbols. Sudoku is pure logic and pattern-spotting; you never add or multiply anything.
How do I get better at Sudoku? Learn to spot “naked” and “hidden” singles first, use pencil notes for candidates, and work the most-filled rows, columns, and boxes.
Is it free? Yes — no signup, no downloads, no installs.