A fresh puzzle, every single time.
Nine rows, nine columns, nine boxes, and the digits 1–9 in each. Every puzzle here is generated on the spot and checked to have exactly one solution — so you can never run out, and you can always trust the logic.
Click a square and type a number, or use the pad. Notes lets you pencil in candidates — arrow keys move around the grid, and N toggles note mode.
The whole game in three rules
Every row, 1 to 9
Each of the nine rows must contain every digit from 1 to 9, with none repeated.
Every column, 1 to 9
The same goes down. Nine columns, nine digits each, no repeats anywhere.
Every box, 1 to 9
And each of the nine 3×3 boxes marked by the thicker lines. Satisfy all three and the puzzle is solved.
Three techniques that crack most grids
Single candidate. Look at one empty square and rule out every digit already present in its row, column and box. If only one survives, it goes there.
Single position. Flip it around — take one digit and one box, and cross out every square it can't occupy. If only one square is left, that's its home.
Pencil first, ink later. On harder grids, use Notes to mark the candidates for each square. Patterns surface on their own once the numbers are written down — a pair of squares sharing the same two candidates locks both digits into that pair, freeing the rest of the row.
Easy and Medium puzzles here fall to the first two techniques alone. Hard and Expert will want notes.
Questions people ask
Yes. Each grid is carved out of a complete solution one square at a time, and after every removal the generator checks that only one solution still exists. If a removal would allow two, it is put back. A puzzle with more than one answer is a broken puzzle, and you will not get one here.
Always. A unique solution means there is a logical path to it. Guessing may be faster on an Expert grid, but it is never necessary.
Mostly how many numbers you start with, and how they are spread out. Easy puzzles here give you about 45, Expert closer to 26. Fewer givens means fewer squares you can settle immediately, so you have to chain more deductions together.
Yes, in your own browser. Close the tab and come back and your grid, your notes and the clock will be where you left them. It is stored on your device only, so it will not follow you to a different browser or computer.
Fancy words instead of numbers?
The crossword is waiting, and the solvers will untangle any letters you throw at them.