Casegrid
Sudoku
Nine rows, nine columns, one answer. Pencil marks included.
Controls — Tap a cell, then a number. Keyboard: 1–9 to fill, P for pencil, Backspace to clear.
How to play
- Tap a cell and a number. Rows, columns and boxes cannot repeat a digit — repeats turn red immediately.
- Turn on Pencil to note candidates in a cell instead of committing to a number.
- Fill all 81 cells. Every puzzle here has exactly one solution, so guessing is never required.
Tips
- Start with the digit that appears most often — the boxes it is missing from are nearly full.
- A digit with two candidate cells in a box can be pencilled rather than guessed.
- On hard, the first move is usually a scan of all nine boxes, not the row in front of you.
About this game
Sudoku on Casegrid generates puzzles rather than replaying a fixed set: a full grid first, then cells taken away one at a time while the puzzle keeps exactly one answer.
Three levels differ only in how many digits you start with — 40, 34 or 28 — which is the honest way to make it harder without changing the rules.
No download, no account, no tracking, no ads.
FAQ
Are the puzzles always solvable by logic alone?
They have exactly one solution. Some hard ones reward a short pencilled chain rather than a single obvious cell.
Is my progress saved?
No — a new puzzle starts fresh. The timer starts on your first number.
What does Hint do?
Fills one cell from the solution. Use it when a puzzle stalls rather than to finish it.
