Goal

Fill every empty cell so each row, column, and 3×3 box contains the digits 1–9 exactly once.

Controls — Desktop

• Click a cell to select it
• Type 1–9 to fill in a number
• Delete / Backspace to erase your entry
• Arrow keys to move between cells

Controls — Mobile

• Tap a cell to select it
• Use the number pad below the grid to enter digits
• Tap ✕ on the pad to erase

Hints & Mistakes

• Conflicts (duplicates in a row, column, or box) are highlighted in red in real time
• Each difficulty gives a limited number of hints — use them wisely
• Mistakes are counted whenever you place a number that conflicts

Is my best time saved?

Yes — best completion time per difficulty is saved in your browser's local storage.

What counts as a mistake?

Any time you place a digit that creates a conflict (duplicate in the same row, column, or box) a mistake is recorded, even if you later correct it.

Do hints affect my score?

Hints are tracked and shown in your completion summary, but they don't affect your best time.

Can I change difficulty mid-game?

Clicking a difficulty button while a game is in progress starts a new game at that difficulty.