Game guide · NEW61
Learn the rules of Classic Sudoku
Make Classic Sudoku your next activity in the game library. Fill all cells with 1–9; do not repeat a symbol in any row, column or region. Keep the game area visible while you use its controls. Check the rule that explains your first action. Use the example below to understand a decision.
An idea for your next attempt
Before your first action, say what you are trying to achieve. Then compare the result with the goal. Use the example to check your reasoning.
Your goal
Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The feedback beside the game helps you follow the round. The example below illustrates a decision.
The steps to play
- Select an empty cell. The original clues cannot be edited.
- Choose a symbol from the number pad, or type it on a keyboard.
- Turn Notes on to record candidate symbols without committing an answer.
- Use Check entries to check your filled values. Hint reveals one value from the verified solution.
- Complete the board, or choose New puzzle for another board.
Using the playing area
Tap or click a cell and use the number pad. Keyboard: arrows select cells; digits (and A–G on 16×16) enter values; Backspace erases. Keep the playing area visible while using these controls. Contact us with the game and device if a control does not respond.
Put the rules into context
On one puzzle in this collection, row 1, column 2 has 9 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Compare this with the rule that governs the move. Notice the change in the playing area.
Keep this in mind
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Check the rule before repeating the action. Locate the buttons and input area before beginning a long round. Use the on-screen labels to avoid an accidental restart.
Helpful answers for players
On this playing page, what is the goal of Classic Sudoku?
Here is the relevant explanation: Fill all cells with 1–9; do not repeat a symbol in any row, column or region.
For a quick reminder, how do I control Classic Sudoku?
Keep this in mind: Tap or click a cell and use the number pad. Keyboard: arrows select cells; digits (and A–G on 16×16) enter values; Backspace erases.
As a new player, what example helps explain Classic Sudoku?
For clarity: On one puzzle in this collection, row 1, column 2 has 9 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
For this browser game, what should I watch out for in Classic Sudoku?
The key detail is this: Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
For my first round, what format does Classic Sudoku offer?
Here is the relevant explanation: Play using the solo mode shown on this page. Read the controls before starting a new round.
On this playing page, which play mode does Classic Sudoku use?
The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
For this browser game, where should I start with Classic Sudoku?
The key detail is this: Select an empty cell. The original clues cannot be edited.
For this browser game, do I need an account or a payment for Classic Sudoku?
The key detail is this: No player account or payment is needed. Game scores are recreational results, not cash prizes.
How can I find Classic Sudoku again?
Use the Games list or save this game page in your browser bookmarks. The Guide is linked from the playing page.
Before I begin, how do I report an issue with Classic Sudoku?
For clarity: Use the contact form and include the game name, browser, device and the actions that led to the issue. Do not send passwords or payment details.