How to Play Sudoku
Everything you need to go from complete beginner to confident solver — rules, techniques, and tips for every level.
🎯 The Objective
Sudoku is a logic-based number puzzle. Your goal is to fill a 9×9 grid so that every row, every column, and every 3×3 box contains each of the digits 1 through 9 — with no repetition.
The puzzle starts with some numbers already placed (called givens). You use logic to figure out where the remaining numbers go. No guessing required!
📋 The Three Rules
- Every row (horizontal line) must contain the digits 1–9, each exactly once.
- Every column (vertical line) must contain the digits 1–9, each exactly once.
- Every 3×3 box (there are 9 of them) must contain the digits 1–9, each exactly once.
▶️ How to Play on This Site
Choose a difficulty
Pick Easy, Medium, Hard, or Expert — or tap the orange button to play today's Daily Challenge shared by all players worldwide.
Select a cell
Click (or tap) any empty cell on the grid to select it. It highlights in violet. You can also use the arrow keys on a keyboard to navigate.
Enter a number
Click a number on the numpad (1–9) or press a number key on your keyboard to place it in the selected cell. Wrong entries turn red.
Use Hint if you're stuck
The green Hint button reveals the correct value for the selected cell. Use it sparingly to keep the challenge!
Complete the grid
Fill every cell correctly and the victory screen appears showing your time, streak, and performance badges.
⚡ Difficulty Levels
| Level | Cells Removed | Best For |
|---|---|---|
| Easy | 30 | Beginners learning the rules |
| Medium | 40 | Casual players, daily practice |
| Hard | 50 | Experienced solvers |
| Expert | 58 | Advanced techniques required |
💡 Solving Tips & Techniques
Scanning
Look at each row and column to identify which numbers are missing. Cross-reference them to find cells that can only hold one value.
Elimination
For each empty cell, list which numbers are already in its row, column, and box. The remaining options narrow down the answer.
Singles
If a number can only go in one cell within a row, column, or box — place it there. This is the most common beginner technique.
Start with boxes
Look for 3×3 boxes that are nearly full. Boxes with 7–8 given numbers are easiest to complete first, building momentum.
Work systematically
Go digit by digit — find all the 1s first, then all the 2s, and so on. This avoids missing obvious placements.
Never guess
Every Sudoku puzzle has a unique solution reachable by pure logic. If you're guessing, go back and look for a step you missed.