Mini Sudoku is Sudoku on a small board. People also call it 4x4 Sudoku or 6x6 Sudoku. The rules are the same as in big Sudoku, so it is a quick way to learn.
The rules
- A 4 by 4 board uses the numbers 1 to 4. Its boxes are 2 squares wide and 2 squares tall.
- A 6 by 6 board uses the numbers 1 to 6. Its boxes are 3 squares wide and 2 squares tall.
- Each row must have every number once.
- Each column must have every number once.
- Each thick-lined box must have every number once.
- You can't change the starting numbers.
Classic Sudoku works the same way on a 9 by 9 board. It uses the numbers 1 to 9 and boxes of 3 by 3.
A worked example
Here is a 6 by 6 board. Each row lists its squares from left to right. Each box covers 2 rows and either columns 1 to 3 or columns 4 to 6.
- Row 1: empty, empty, empty, empty, 5, 6.
- Row 2: empty, empty, empty, 1, 2, 3.
- Row 3: 2, empty, empty, empty, 6, empty.
- Row 4: empty, 6, 1, empty, 3, empty.
- Row 5: 3, empty, 5, 6, 1, 2.
- Row 6: empty, 1, 2, 3, empty, empty.
- Row 5 holds 3, 5, 6, 1 and 2. Only 4 is missing, so its empty square takes 4.
- Column 5 holds 5, 2, 6, 3 and 1. Only 4 is missing, so row 6, column 5 takes 4.
- Row 6 now has one empty square at each end. It still needs 5 and 6.
- The bottom-right box already has a 6, in row 5. So row 6, column 6 cannot be 6. It takes 5.
- That leaves 6 for row 6, column 1.
- Now look at row 1, column 4. Row 1 has 5 and 6. Column 4 has 1, 6 and 3. Its box has 5, 6, 1, 2 and 3.
- The only number left for that square is 4, so it goes there.
- Column 6 now holds 6, 3, 2 and 5. It still needs 1 and 4, in rows 3 and 4.
- Row 4 already has a 1. So row 4, column 6 takes 4, and row 3, column 6 takes 1.
- Keep going the same way. The finished rows read 123456, 456123, 234561, 561234, 345612 and 612345.
Beginner techniques
The last number
Find a row, column or box with just 1 empty square. Fill it with the missing number.
Only one place
Pick a number and a row, column or box. If that number fits in only 1 square there, put it there. It does not matter if other numbers seem to fit that square too.
Only one number
Pick an empty square. Check which numbers its row, column and box already have. If only 1 number is left, it goes there.
Locked in a row
Sometimes a number fits in only 1 row inside a box. Then that row can't hold the number outside the box. The same works for columns.
Two squares, two numbers
Find 2 squares that can only hold the same 2 numbers. Those 2 numbers belong in those 2 squares. Other squares in the row, column or box they share can't hold either number.
Common mistakes
- Checking the row and column but forgetting the box.
- Thinking the boxes on a 6 by 6 board are 3 squares tall. They are 2 tall and 3 wide.
- Filling in a guess as an answer. Use Notes for numbers that might fit.
- Staring at one stuck square. Switch to another row, column or box.
Questions
Is Mini Sudoku the same as Sudoku?
Yes, the rules are the same. Only the board is smaller. Classic Sudoku uses a 9 by 9 board with the numbers 1 to 9.
Is it the same as LinkedIn's Mini Sudoku?
LinkedIn's daily Mini Sudoku uses the same rules on a 6 by 6 board. Its boxes are 2 rows tall and 3 columns wide, like the 6 by 6 boards in Quirk. Quirk also has 4 by 4 boards.
What sizes are there in Quirk?
Quirk has 4 by 4 boards with the numbers 1 to 4. It also has 6 by 6 boards with the numbers 1 to 6.
Do I ever need to guess?
No. Every puzzle has exactly one answer, and you can reach it by checking rows, columns and boxes. If you get stuck, a hint shows the next step and says why.
What are notes?
Turn on Notes to write small numbers that might fit in a square. Notes don't count as answers.
Is Mini Sudoku good for beginners?
Yes. Start with 4 by 4 boards. The last number and only one place are often all you need there.
Related puzzles
Playing it in Quirk
Tap a square, then a number to fill it. Tap another number to change it, or tap Clear to empty it.
Turn on Notes to write small numbers that might fit. Notes don't count as answers. You can undo a move or reset the board at any time.
