How SudoCraft Works

SudoCraft is a two-in-one sudoku tool. Use the Generate page to create printable puzzles in different sizes and difficulties, pick your own colors, and download them as images - perfect for puzzle books, classrooms or printed activities. Use the Play page to solve sudoku directly in your browser, with hints, mistake tracking and a timer.

Sudoku is played on a grid divided into smaller boxes. The goal is to fill every empty cell with a number so that:

• Each row contains every number exactly once.
• Each column contains every number exactly once.
• Each smaller box contains every number exactly once.

Every puzzle on SudoCraft has exactly one valid solution - there is always a logical way to solve it without guessing.

Alongside classic sudoku, SudoCraft can generate, play and solve three other puzzle types, each adding its own extra rule on top of the normal row/column/box logic:

• Kropki Sudoku - small dots appear between some neighbouring cells. A white dot means the two numbers are consecutive (like 4 and 5); a black dot means one number is exactly double the other (like 3 and 6). If there is no dot between two cells, neither relationship applies - that absence is a real clue too, and it is often enough to let a Kropki puzzle start with far fewer given numbers than a classic one.
• Samurai Sudoku - five 9×9 grids overlap into one large puzzle: one in the centre and one in each corner, with each corner sharing a 3×3 box with the centre grid. Every grid still follows the usual rules on its own, but a number placed in a shared box affects two grids at once, making this the longest and most demanding puzzle on SudoCraft.
• Arrow Sudoku - circles are drawn on some cells, each with an arrow leading out across one or more neighbouring cells. The digits along that arrow must add up to exactly the number inside its circle. Arrows can run straight, diagonally, or bend once around a corner - harder difficulties use longer, more complex arrows.

Switch between all four types on the Generate, Play and Solve pages using the "Sudoku type" menu.

• 9×9 - the classic sudoku. Numbers 1–9, with nine 3×3 boxes.
• 6×6 - a smaller version. Numbers 1–6, with six 2×3 boxes.
• 3×3 - a quick warm-up. Numbers 1–3; since the single box covers the whole grid, it plays like a mini logic puzzle based only on rows and columns.

• Scan rows, columns and boxes for numbers that are almost complete - that is usually where the next clue is hiding.
• Look for cells with only one possible number left, based on what already exists in their row, column and box.
• Stuck? Use the Hint button on the Play page to reveal one correct cell without giving up the rest of the puzzle.
• Made a mistake? Wrong numbers turn red immediately, and Undo takes back your last move.