Today Sudoku contains very many types of variant Sudoku, more types of Sudoku puzzles are still under continuous development, please continue to pay attention to Sudoku today.

- Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
- A number at the edge of the diagram indicates the difference between the first and the last number in the corresponding row or column.

- Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
- A number at the edge of the diagram indicates the difference between the first and the last number in the corresponding row or column.

- Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.
- Some thermometer shapes are placed in the grid. Digits are strictly increasing from the round bulb of the thermometer to each flat end.

- Some thermometer shapes are placed in the grid. Digits are strictly increasing from the round bulb of the thermometer to each flat end.

- Sum and difference of two orthogonally adjacent numbers must not be 5.

- Sum and difference of two orthogonally adjacent numbers must not be 5.

- Adjacent cells with digits summing to 5 are marked by V, while those summing to 10 are marked by X. Not all possible V and X are marked.

- Adjacent cells with digits summing to 5 are marked by V, while those summing to 10 are marked by X. Not all possible V and X are marked.

- Digits in adjacent cells cannot be consecutive.

- Digits in adjacent cells cannot be consecutive.

- The number in a cell with an arrow must not be repeated in a cell the arrow points to.

- The number in a cell with an arrow must not be repeated in a cell the arrow points to.

- A number between two cells indicates the sum of the numbers in these cells. A number between four cells indicates the sum between two diagonally adjacent cells, either top left + right bottom (\) or top right + bottom left (/).

- A number between two cells indicates the sum of the numbers in these cells. A number between four cells indicates the sum between two diagonally adjacent cells, either top left + right bottom (\) or top right + bottom left (/).

- Numbers with arrows indicate sum of the numbers in each direction.

- Numbers with arrows indicate sum of the numbers in each direction.

- Numbers with arrows indicate sum of the numbers in each direction.

- Numbers with arrows indicate sum of the numbers in each direction.

- A cross between two cells indicates that the product of the numbers in these cells is less than 10. A plus between two cells indicates that the sum of the numbers in these cells is less than 10. If the sum and product are less than 10, then there is a cross between these cells. If there is no sign between two cells, then both sum and product are at least 10.

- A cross between two cells indicates that the product of the numbers in these cells is less than 10. A plus between two cells indicates that the sum of the numbers in these cells is less than 10. If the sum and product are less than 10, then there is a cross between these cells. If there is no sign between two cells, then both sum and product are at least 10.

- The connected shaded cells contain each digit from 1 to 9.

- The connected shaded cells contain each digit from 1 to 9.

- If absolute difference between two digits in neighbouring cells equals 1, then they are separated by a white dot. If the digit is a half of digit in the neighbouring cell, then they are separated by black dot. The dot between 1 and 2 can be either white or black.

- If absolute difference between two digits in neighbouring cells equals 1, then they are separated by a white dot. If the digit is a half of digit in the neighbouring cell, then they are separated by black dot. The dot between 1 and 2 can be either white or black.

- A number between two cells indicates the sum of the numbers in these cells. A number between four cells indicates the sum between two diagonally adjacent cells, either top left + right bottom (\) or top right + bottom left (/).

- A number at the edge of the diagram indicates the difference between the highest and the lowest number in the first three cells in the corresponding row or column.

- A number at the edge of the diagram indicates the difference between the highest and the lowest number in the first three cells in the corresponding row or column.

- Digits do not repeat along the marked diagonals.

- Digits do not repeat along the marked diagonals.

- Numbers in the red circle are not allowed appears in four squares which is nearby the intersection of row and column red circles.

- Numbers in the red circle are not allowed appears in four squares which is nearby the intersection of row and column red circles.

- The connected shaded cells contain each digit from 1 to 9.

- The connected shaded cells contain each digit from 1 to 9.

- There are some dots between cells. The numbers on each side of a dot must always be consecutive. Not all possible dots are marked.
- Digits outside the grid indicate the sum of the first 3 digits in the corresponding direction.

- There are some dots between cells. The numbers on each side of a dot must always be consecutive. Not all possible dots are marked.
- Digits outside the grid indicate the sum of the first 3 digits in the corresponding direction.

- Grey cells in the grid represent many cloned areas. Digits in these areas on corresponding positions must be identical. Cloned areas are only moved, without rotation or reflection.

- Grey cells in the grid represent many cloned areas. Digits in these areas on corresponding positions must be identical. Cloned areas are only moved, without rotation or reflection.

- Grey cells in the grid represent many cloned areas. Digits in these areas on corresponding positions must be identical. Cloned areas are only moved, without rotation or reflection.