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.
- Digits have to be place in accordance with the “greater than” signs.

- 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.
- Digits have to be place in accordance with the “greater than” signs.

- 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.
- Each set of four digits in the intersection of two lines indicates the digits that have to be placed in the four adjacent cells.

- Each set of four digits in the intersection of two lines indicates the digits that have to be placed in the four adjacent cells.

- Each number at the intersection of four cells is the sum of digits in those four cells.

- Each number at the intersection of four cells is the sum of digits in those four cells.

- The arrows outside the grid indicate that the nearest three digits in the corresponding direction are in ascending or descending order (the highest number is always in the direction of the arrow). All possible arrows are given, so if there is no arrow, the first three digits do not form an increasing sequence in either direction.

- The arrows outside the grid indicate that the nearest three digits in the corresponding direction are in ascending or descending order (the highest number is always in the direction of the arrow). All possible arrows are given, so if there is no arrow, the first three digits do not form an increasing sequence in either 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.

- Apply Classic Sudoku rules. Within each coloured region each digit must appear exactly once.

- Apply Classic Sudoku rules. Within each coloured region each digit must appear exactly once.

- Cells with circles must contain digits 1-2-3, cells with squares must contain digits 4-5-6, blank cells must contains digits 7-8-9.

- Cells with circles must contain digits 1-2-3, cells with squares must contain digits 4-5-6, blank cells must contains digits 7-8-9.

- Each number at the intersection of four cells is the sum of digits in those four cells.

- Each number at the intersection of four cells is the sum of digits in those four cells.

- If a shaded cell and a white cell are adjacent then the digit in the shaded cell is greater.

- If a shaded cell and a white cell are adjacent then the digit in the shaded cell is greater.

- Everywhere 2 odd and 2 even digits form a 2x2 checkerboard pattern, a Battenburg marking is given. A checkerboard pattern is a 2x2 area of cells where the top-left and bottom-right cells are of one type and the top-right and bottom-left cells are of another type. All possible dots are marked.

- Everywhere 2 odd and 2 even digits form a 2x2 checkerboard pattern, a Battenburg marking is given. A checkerboard pattern is a 2x2 area of cells where the top-left and bottom-right cells are of one type and the top-right and bottom-left cells are of another type. All possible dots are marked.

- 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.

- A number in a squared cell indicates how many different numbers the four diagonally adjacent cells contain. A number in a circled cell indicates how many different numbers the eight orthogonally and diagonally adjacent cells contain.

- A number in a squared cell indicates how many different numbers the four diagonally adjacent cells contain. A number in a circled cell indicates how many different numbers the eight orthogonally and diagonally adjacent cells contain.

- The four corner boxes contain the same digit in symmetric positions about the centre.

- The four corner boxes contain the same digit in symmetric positions about the centre.

- 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.

- Apply Classic Sudoku rules. Within each coloured region each digit must appear exactly once.

- Apply Classic Sudoku rules. Within each coloured region each digit must appear exactly once.

- Digits do not repeat along the marked diagonals.

- Digits do not repeat along the marked diagonals.

- Apply Classic Sudoku rules. Within each coloured region each digit must appear exactly once.

- Apply Classic Sudoku rules. Within each coloured region each digit must appear exactly once.

- The same numbers are not chess-knight move connected.

- The same numbers are not chess-knight move connected.

- Digits outside the grid indicate the sum of the first 3 digits in the corresponding direction.

- Digits outside the grid indicate the sum of the first 3 digits in the corresponding direction.

- The four corner boxes contain the same digit in symmetric positions about the centre.

- The four corner boxes contain the same digit in symmetric positions about the centre.