How it works
This page makes free printable sudoku 6 per page, or 1, 2 or 4 per page when you want bigger squares. Choose a 9 by 9 grid, or a 6 by 6 or 4 by 4 grid for children, and one of 4 levels. Each puzzle is new, each is tested to make sure it has exactly one answer, and the answers print on their own page.
Read the full guide
Grid size, level and puzzles per page
The 9 by 9 grid is the classic puzzle: every row, column and 3 by 3 box holds the digits 1 to 9 once each. The 6 by 6 grid uses 1 to 6 with boxes 3 squares wide and 2 tall. The 4 by 4 grid uses 1 to 4 with 2 by 2 boxes. Pick a Level from Easy to Expert, then 1, 2, 4 or 6 in the Per page menu. For younger children or tired eyes, the same menu has one big puzzle: 1 per page, large print. New puzzles changes every grid, and every puzzle on a sheet is different.
Exactly one answer, tested first
A proper sudoku has one answer. If a puzzle has two, the person solving it reaches a point where logic runs out and only a guess is left. The printed answer may then not match a grid that is perfectly valid. So a solver program tries each new puzzle before you see it and rejects any that can be finished in more than one way. There is plenty to draw from. A 9 by 9 grid can be filled in 6,670,903,752,021,072,936,960 ways. A 6 by 6 grid has 28,200,960 and a 4 by 4 grid has 288.
Printing on Letter or A4
Six puzzles sit 2 across and 3 down on an upright sheet of Letter or A4, which leaves each 9 by 9 grid just under 3 inches wide. That suits the easier levels and saves paper in a pack. On harder levels, solvers pencil small candidate digits into the corners of a square, and 2 or 4 per page gives them room. The answers print on a separate last page, numbered to match, so you can hand out the puzzles and keep the key. Share this sheet, under More options, makes a link that opens the same puzzles.
- Teach the 4 by 4 grid first. The rule is the same as in the big puzzle.
- Tell new solvers that no arithmetic is involved. The digits are only 9 different symbols.
- Print one answer page and pin it up, so pupils check their own grids.
- Add a cryptogram to the pack for anyone who prefers words to numbers.
Questions and answers
Can I make a color sudoku printable or a Halloween sudoku printable from these?
Yes, with a key. For the color version, print 4 by 4 puzzles and write a key on the board: 1 is red, 2 is blue, 3 is yellow, 4 is green. Pupils color each square, clues included. For Halloween, make the key pumpkin, bat, ghost and spider, and have pupils draw the pictures. The logic is unchanged, and children who are unsure of their digits can join in.
Is there a 16x16 sudoku printable or a monster sudoku printable here?
No. The largest grid on this page is 9 by 9. A 16 by 16 grid has 4 by 4 boxes and 16 symbols, usually the numbers 1 to 16 or the letters A to P. Monster sudoku is a common name for the same giant grid. For a long puzzle from this page, print an Expert 9 by 9 puzzle at 1 per page.
Do these work as a diagonal sudoku printable or an irregular sudoku printable?
No, these are classic puzzles. A diagonal sudoku adds a rule: each of the two long diagonals must also hold every digit once. An irregular sudoku, also called jigsaw sudoku, swaps the square boxes for uneven shapes of 9 squares. The puzzles made here are not tested against either rule, so adding the diagonal rule yourself would contradict the printed answer.
Where did sudoku come from?
The modern puzzle first appeared in an American puzzle magazine in 1979 under the name Number Place. It was most likely designed by Howard Garns, a retired architect from Indiana. A Japanese publisher picked it up in 1984 and gave it a name that was later shortened to sudoku, meaning roughly that the digits must be single. British newspapers began printing it in 2004.