How to Play Sudoku
Sudoku is the world's most popular number-placement puzzle and one of the purest tests of logical reasoning. The rules are elegantly simple: fill a 9×9 grid so that every row, every column, and every 3×3 box contains the digits 1 through 9 exactly once. No math is required — it is entirely about pattern recognition and elimination. Whether you are a first-time player or a seasoned solver, Sudoku offers a deeply satisfying mental workout every single time.
How to Play
Click or tap an empty cell to select it, then press a number key (1–9) or tap one of the number buttons below the grid to place a digit. If the digit violates the rules (appears twice in the same row, column, or 3×3 box), it will be highlighted in red if error highlighting is enabled. You have 3 errors allowed before the game ends. Press 0, Delete, or Backspace to erase a cell. Use arrow keys to navigate between cells.
Notes mode: Toggle notes (pencil marks) with the ✏️ button or press N. In notes mode, clicking a number adds or removes a small pencil mark in the cell, helping you track possible values. Undo: Press Ctrl+Z or the ↩ button to reverse your last action. Pause: Press the ⏸ button to pause the timer and hide the board — useful for breaks.
Four difficulty levels are available: Easy (38+ given digits), Medium (30–37 given), Hard (25–29 given), and Expert (22–24 given). Higher difficulties have fewer starting clues, requiring more advanced solving techniques.
Daily Challenge
The 📅 Daily Challenge generates the same puzzle for everyone each day using a date-based seed. Complete today's puzzle, see your time, and come back tomorrow for a fresh challenge. It is a great way to build a daily habit and track your improvement over time.
History & Origin
Although Sudoku feels timeless, its modern form only emerged in 1979 when Howard Garns, a retired architect from Indianapolis, designed a puzzle called "Number Place" for Dell Magazines. The puzzle was introduced to Japan by publisher Nikoli in 1984, who shortened the name to "Sudoku" (meaning "single number"). It exploded into a global phenomenon in 2004–2005 when Wayne Gould, a retired Hong Kong judge, began supplying computer-generated puzzles to The Times of London. Within months, Sudoku appeared in newspapers worldwide and became the most popular logic puzzle in history. For solving strategies from basic to advanced, see our Sudoku Solving Techniques guide.
Strategy & Tips
- Scan for singles. Look for rows, columns, or boxes where only one empty cell remains for a particular digit. These "naked singles" are the easiest placements to spot.
- Use pencil marks. In harder puzzles, notes mode is essential. Write down all possible candidates for each cell, then eliminate candidates as you fill in other cells.
- Work the intersections. When a digit can only go in one row or column within a 3×3 box, you can eliminate that digit from the rest of that row or column outside the box. This technique is called "pointing pairs."
- Try the "hidden single" technique. Even if a cell has multiple candidates, if a digit can only appear once within a row, column, or box, that digit must go in that cell.
- Start with the most constrained areas. Look at rows, columns, or boxes that already have the most digits filled in — they have the fewest possibilities remaining.
- Never guess on Easy or Medium. If you feel the need to guess, you have missed a logical deduction. Take a step back and scan again.
Frequently Asked Questions
Does Sudoku require math?
No. Despite using numbers, Sudoku is purely a logic puzzle. The digits could be replaced with letters, colors, or symbols and the puzzle would work identically. No addition, subtraction, or arithmetic of any kind is needed.
Can every Sudoku puzzle be solved without guessing?
Properly constructed Sudoku puzzles always have a unique solution reachable through logic alone, without guessing or trial-and-error. All puzzles generated on MiniGamePlanet meet this standard.
What is a good time for medium Sudoku?
For a medium-difficulty puzzle, 5–10 minutes is typical for an experienced solver. Beginners may take 15–30 minutes, which is perfectly fine. Speed comes naturally with practice as you learn to recognize patterns faster.
Play Sudoku free in your browser right now — no download, no account needed. Pick a difficulty, start filling cells, and enjoy one of the greatest puzzles ever created.