🛠️ How to Use the Sudoku App

🎮 Input Modes:

• Digit-First: Select a digit first, then click a cell to place it.
• Cell-First: Click a cell first, then select a digit to insert.

🧩 Features:

• Undo: Reverts your last move.
• Highlighting: Highlights all cells with the selected digit.
• Candidates: Displays possible digits for empty cells.
• 💾 Save/♻️ Restore: Temporarily stores or retrieves your progress.
• Print: Opens a printable version of the puzzle.

⌨️ Keyboard Controls (Cell-First Mode Only):

• Arrow keys: Move between cells
• 1–9: Insert digit
• 0 / Backspace / Delete: Clear selected cell

📖 Sudoku Rules

Fill the grid so that every row, column, and 3×3 block contains the digits 1 through 9 exactly once. Some numbers are already given — your task is to fill in the rest without duplicates!

What Is Sudoku?

Sudoku is a logic-based puzzle played on a 9×9 grid. The goal is to fill every row, column, and 3×3 block with the digits 1 through 9 — without repetition. Each puzzle starts with some numbers already filled in, and it's your task to complete the rest using logic, not guessing.

Why Play Sudoku Online?

• ✔ Train memory, concentration, and logical thinking
• ✔ Play anytime — no downloads or registration needed
• ✔ Multiple difficulty levels for beginners and experts
• ✔ Smart features: candidates, undo, highlighting, save/restore
• ✔ Fully mobile-friendly and desktop-optimized

Learn More

New to Sudoku? Try our Step-by-Step Tutorial. Interested in how Sudoku evolved? Visit the History of Sudoku.

Play Sudoku online anytime, challenge yourself, and enjoy unlimited puzzles to improve your skills while having fun!