About game
Fill every empty cell with numbers from one to nine while ensuring no duplicates appear in your rows, columns, or smaller squares. You manage the grid by selecting specific tiles and assigning values until the entire board reaches completion. Logic remains your primary tool for solving this classic puzzle while you navigate through increasingly complex layouts. Switch between normal entry, note-taking, and erasure modes to keep your workspace organized during intense sessions. You gain satisfaction from watching the board fill up correctly as your brain training progresses. This digital board keeps track of your moves so you can focus entirely on the challenge at hand. Sharpen your mental agility whenever you need a quick break from your daily routine. Play Classic Sudoku (9x9) directly in your browser without any annoying downloads or signups required. Classic Sudoku (9x9) turns simple digit placement into an addictive mental workout that tests your patience and analytical speed.
How to play
Your task is to fill all the empty cells of the 9×9 field with numbers from 1 to 9, following three basic rules:
There should be no repeating numbers in a row (all numbers from 1 to 9).
In a column, each number appears only once.
In each small 3×3 square (highlighted in bold), the numbers should also not be duplicated.
Management
To enter a digit, click on an empty cell (it will be highlighted), then click on the desired digit on the control panel.
The editing modes are switched by the "Eraser" button:
The green indicator (note mode) allows you to enter multiple digits in a cell.
The red indicator (clear mode) completely removes all digits and notes from any cell when clicked.
The white indicator (normal mode) is the standard mode for entering final digits (like a pen).
Hint: Click on the "Hint" button when a cell is highlighted, and one correct digit will be automatically inserted into the cell.
Features
- Note mode: Keep track of potential candidates by toggling the green indicator to pencil in multiple numbers per cell.
- Eraser tool: Clear mistakes instantly by switching to the red indicator mode to remove incorrect digits or notes.
- Smart hint system: Use the hint button to reveal the correct digit for any highlighted cell when you get stuck.
- Visual feedback: Highlight your current selection to ensure you maintain focus on the specific section of the grid.
Who is it for
Puzzle lovers who enjoy sharpening their minds with classic logic challenges will find this ideal. Fans of math-based brain training who want to test their focus on a clean digital board. Casual players looking for a quick, stimulating way to pass time during short breaks without complex setup.
Controls
Select cell
Tap the empty grid square on mobile or click it with your mouse.
Input digit
Tap or click the desired number on the bottom control panel.
Change mode
Tap the eraser or indicator icons to switch between note, clear, and normal entry modes.
FAQ
Is Classic Sudoku (9x9) free to play?
›
Yes, you can play Classic Sudoku (9x9) completely free directly in your web browser.
Can I play Classic Sudoku (9x9) on my phone?
›
Absolutely, Classic Sudoku (9x9) is fully optimized for mobile touchscreens and desktop browsers alike.
How do I remove a number in Classic Sudoku (9x9)?
›
Switch to the clear mode using the red indicator button and click the cell you wish to empty.
