Game guide · VISITPHONE
Diagonal Sudoku: what to know before playing
Try Diagonal Sudoku at your own pace and keep its objective in view. Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The two long diagonals must also contain each symbol once. Use the example below to understand a decision. Identify the playing area and the controls you need. Choose a clear next step rather than rushing through the instructions.
A small practice goal
Compare the worked example with your own position. Use the reasoning, not an answer copied from a different board. Refer to the controls when needed.
What the game asks you to do
Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The two long diagonals must also contain each symbol once. The feedback beside the game helps you follow the round. Take a moment to understand the current position.
Work through the instructions
- 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.
Keyboard and screen controls
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. Read the example below alongside these instructions.
See how the rules apply
On one puzzle in this collection, row 1, column 5 has 3 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Focus on why the action is allowed, not only its outcome. Look for the relevant detail.
Pay attention to this rule
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. Compare the situation with the worked example. Keep the stated aim separate from side details such as animation or appearance. Progress is measured by the game’s own completion or scoring rules.
Questions that come up during play
For this browser game, what is the goal of Diagonal Sudoku?
For clarity: Fill all cells with 1–9; do not repeat a symbol in any row, column or region. The two long diagonals must also contain each symbol once.
On this playing page, how do I control Diagonal 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.
For this browser game, what example helps explain Diagonal Sudoku?
Before filling a cell, compare the symbols already used in its row, column and 3 × 3 region. A candidate must be absent from all three. The two long diagonals must also contain each symbol once.
While learning, what should I watch out for in Diagonal Sudoku?
Here is the relevant explanation: Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule.
For this browser game, what format does Diagonal Sudoku offer?
Keep this in mind: Play using the solo mode shown on this page. Read the controls before starting a new round.
As a new player, which play mode does Diagonal Sudoku use?
Keep this in mind: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
Before I begin, where should I start with Diagonal Sudoku?
Keep this in mind: Select an empty cell. The original clues cannot be edited.
For this browser game, do I need an account or a payment for Diagonal Sudoku?
Keep this in mind: No player account or payment is needed. Game scores are recreational results, not cash prizes.
Before I begin, how can I find Diagonal Sudoku again?
For clarity: Use the Games list or save this game page in your browser bookmarks. The Guide is linked from the playing page.
For this browser game, how do I report an issue with Diagonal Sudoku?
Keep this in mind: 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.