6×6 Sudoku

Play 6×6 sudoku online for free: the middle step between 4×4 sudoku and the classic 9×9 grid, with numbers 1 to 6, boxes that are 2 squares tall and 3 squares wide, and a new puzzle every time. Each puzzle starts with 16 of the 36 squares filled in and has exactly one answer, so it is sudoku for kids that makes them think without being a marathon. Use the hint button when you are stuck, or print 6×6 sudoku puzzles to solve on paper.

6×6 sudoku online: play and print

Play the 6×6 sudoku game above, then print more puzzles for the classroom or the car. The first picture below is a printable medium 6×6 page with an answer key, the second is a picture version that uses shapes in place of numbers, and the last two show the online game with a mistake in red and a nearly finished grid.

How to play 6×6 sudoku

1. Fill every row, column and box: each of the six rows, six columns and six boxes must contain the numbers 1 to 6 exactly once.
2. Mind the boxes: a 6×6 box is 2 rows tall and 3 columns wide, which is different from the square boxes in 4×4 and 9×9 sudoku. The thick lines show where each box starts and ends.
3. Tap a square, then tap a number, or type it on a keyboard. Wrong numbers turn red and add to the mistakes counter.
4. Use Erase to clear a square and Hint to fill in one square when you are stuck.

Worked example: solve a 6×6 sudoku step by step

This 6×6 sudoku has 14 numbers given. Every step below is a square that has only one possible number, found by checking its row, its column and its box:

1. Row 2, column 5: the row has 1, 3 and 6, the column has 2, 4 and 6 and the box has 2 and 6, so the only number that fits is 5.
2. Row 2, column 6: the row has 1, 3, 5 and 6, the column has 1, 2, 3 and 5 and the box has 2, 5 and 6, so the only number that fits is 4.
3. Row 2, column 2: the row has 1, 3, 4, 5 and 6, the column has no numbers yet and the box has 1 and 3, so the only number that fits is 2.

Continue the same way and the grid fills in. Here is the finished solution:

6×6 sudoku strategies that work

• Scan one number at a time: pick the number that appears most often, then see where else it can go in each row, column and box.
• Look for the only square: if a number has just one possible square in a row, column or box, it goes there.
• Look for the only number: a square whose row, column and box already contain five different numbers can only hold the sixth.
• Use pencil marks: on paper, write the two or three possible numbers small in a square. When one number is ruled out everywhere else, the marks tell you where it goes.
• Work on the fullest box first, because it has the fewest possibilities.

The how to solve sudoku guide explains each strategy with pictures, and the Wikipedia Sudoku article covers the history of the puzzle.

Medium kids sudoku: why 6×6 is the middle step

A 4×4 puzzle can often be solved in a few minutes, while a 9×9 puzzle takes longer and needs more patience. The 6×6 grid is the medium kids sudoku in between: there are enough squares that you must work out a few steps in a row, but few enough that a child can hold the whole grid in their head. Most children who can solve 4×4 puzzles quickly are ready to try 6×6 sudoku.

The number of different 6×6 solution grids is 28,200,960, so you will not run out of new puzzles. Wikipedia’s mathematics of Sudoku article gives the counts for other sizes.

Picture and number versions to print

Use the printable sudoku maker to make 6×6 puzzles in easy, medium or hard, with numbers or with shapes, one, two, four or six to a page, and with an optional answer key. Black-and-white ink is available for classroom photocopying, and Letter or A4 paper.

Ways to use 6×6 sudoku with children

• Homework break: one puzzle is a calm five to fifteen minute break between subjects.
• Partners: one child places numbers and the other says why, which turns solving into explaining.
• Race the clock: the timer in the game shows how long each puzzle takes, so children can try to beat their own time.
• Quiet time: print a puzzle for waiting rooms, travel and rainy days.

6×6 sudoku: frequently asked questions

What age is 6×6 sudoku for?

Children aged about 7 to 9 usually enjoy 6×6 sudoku, once they can solve 4×4 puzzles comfortably.

How are the boxes arranged in 6×6 sudoku?

Each box is 2 rows tall and 3 columns wide, and there are six boxes in the grid. Each box must contain the numbers 1 to 6 once.

How many numbers are filled in at the start?

Each puzzle starts with 16 of the 36 squares filled in, so 20 squares are left to solve.

Does every puzzle have only one answer?

Yes. Every puzzle has exactly one solution, so it can always be solved by logic without guessing.

What is the difference between 6×6 and 9×9 sudoku?

9×9 sudoku has 81 squares, 3 × 3 boxes and the numbers 1 to 9, so it takes longer and needs more strategies. 6×6 sudoku is the quicker step up from 4×4.

Can I play 6×6 sudoku on a phone?

Yes. The numbers keypad is built for touch, and the game also works with a keyboard and mouse.

Is 6×6 sudoku free, and do kids need an account?

Yes, it is free, and no account is needed. Best scores are saved only in the browser on this device.

More sudoku and puzzle games

• 4×4 sudoku for first puzzles
• Easy sudoku, medium sudoku and hard sudoku for 9×9 grids
• Printable sudoku maker with answer keys
• All learning games