Sudoku
Fill in digits 1–9 so every row, column and 3×3 box holds all nine with no repeats. Each board has a unique solution.
Sudoku is the world's favorite number puzzle, and this version keeps it clean and focused. You fill a 9×9 grid with digits so that every row, column, and 3×3 box holds all nine numbers with no repeats. Each board has a single unique solution, so every answer can be reasoned out — no guessing required.
How to play
Tap a cell to select it, then tap a number on the keypad to place it. Use the ✎ button to toggle pencil-note mode for jotting several small candidates in a cell, and ⌫ to erase. A cell turns red when it conflicts with another number, helping you catch mistakes early.
Tips
- Scan for cells or units where only one candidate can legally fit, and lock those in first.
- Use pencil notes to track the remaining possibilities in tricky cells so you don't recompute them each pass.
- When a digit is nearly complete across the grid, hunt for the boxes still missing it — they often resolve quickly.
- Treat every red cell as a signal to stop and re-check, since one bad entry can cascade.
If you love this kind of logic, try the cross-sums of Kakuro or the picture-building Nonogram.
Objective
Fill the whole grid so every row, column and 3×3 box contains 1–9 with no repeats.
Controls
- Tap a cell to select it
- Tap a number on the pad to place it
- The ✎ button toggles notes (small candidates)
- The ⌫ button erases
Tips
- A red cell means the digit repeats in that row, column or box
- Use notes to track the remaining candidates for a cell