Game guide · HNSGYQT
Learn your way around Diagonal Sudoku
Open Diagonal Sudoku, check the instructions and begin a round. 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. Keep the game area visible while you use its controls. Identify the playing area and the controls you need. Keep the game area visible while you use its controls.
Something to practise
Watch the feedback after an action. A message can explain whether the input was accepted or whether a rule needs attention. Refer to the controls when needed.
The goal to keep in mind
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. Read that aim before choosing your first action. Return to the instructions when a step is unclear.
How to proceed
- 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.
How to interact with the game
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. Read a button’s label before selecting it. Avoid pressing the same control repeatedly while a move is being processed.
An example to follow
On one puzzle in this collection, row 1, column 1 has 2 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry. Your next round may have a different position, so inspect it before acting. Keep the game’s format in mind.
A mistake to avoid
Notes are reminders, not final entries. A full board only counts as complete when it satisfies every rule. A different version of the game may use a different rule. Watch the feedback after an action. A message can explain whether the input was accepted or whether a rule needs attention.
If you are unsure
As a new player, what is the goal of Diagonal Sudoku?
Keep this in mind: 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.
For a quick reminder, 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 a quick reminder, what example helps explain Diagonal Sudoku?
The key detail is this: On one puzzle in this collection, row 1, column 3 has 1 in its solution. Read the clues on your current board before using that value; another puzzle can need a different entry.
When I return, 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.
On this playing page, 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.
Which play mode does Diagonal Sudoku use?
The key detail is this: The mode on this page is Solo. Same-device play uses one screen; this game library does not provide internet matchmaking.
While learning, where should I start with Diagonal Sudoku?
For clarity: 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?
The key detail is this: No player account or payment is needed. Game scores are recreational results, not cash prizes.
While reading the Guide, how can I find Diagonal Sudoku again?
Keep this in mind: Use the Games list or save this game page in your browser bookmarks. The Guide is linked from the playing page.
As a new player, how do I report an issue with Diagonal Sudoku?
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.