Christmas Sudoku: 15 Free Printable Puzzles in Three Levels
Fifteen printable Christmas sudoku puzzles in easy, medium and hard, 9x9 grids, each with its own answer page. Graded by solving method, not clue count.
It is a little past ten on a December night. The wrapping is done, badly but done, and the tree lights are the only thing still burning in the room. You do not want another screen. You want a pencil, one page, and something that ends in a definite way.
That is what this set is for. Fifteen Christmas sudoku puzzles, five easy, five medium, five hard, each printed on its own US Letter page with its own holiday artwork behind the grid. Every grid has exactly one solution, and every grid has its own answer page. All fifteen are free printable sudoku puzzles, answer sheets included, nothing held out.
These are ordinary number puzzles: 9x9 grids, the digits 1 through 9, nine rows, nine columns, nine boxes, no repeats anywhere. No symbols standing in for numbers and no variant rules to learn. This is a printable Christmas sudoku set for people who already know how sudoku works and want the holiday on the paper rather than in the rules.
How the three levels were set
The level of a puzzle here is not the number of clues it starts with. It is what the puzzle makes you do.
Most printable sudoku puzzles get labeled easy, medium and hard without anyone saying what the labels mean. In this set each level was checked by solving method, one technique at a time, and the grid was filed by the first method that could not finish it.
An easy sudoku here means something precise. It can be solved by scanning and nothing else. You look along a row, a column or a box, you find the square where only one number will fit, you write it in, and you repeat that until the grid is full. You never have to write a note in a corner. You never have to hold two possibilities in your head at once.
The sudoku medium level in this set is defined by the moment that stops working. On the medium five, scanning runs out somewhere between 39 and 59 of the 81 squares. The grid goes quiet. Nothing is forced anymore, and the only way forward is candidate work: writing the short list of numbers each empty square can still take, then reading those lists against each other. Naked and hidden pairs, triples, and pointing pairs finish all five.
At the sudoku hard level, that is not enough either. On the hard five, candidate work on its own leaves between 36 and 57 of the 81 squares still empty. What remains needs chains: you follow a consequence several steps out, see where it collides with itself, and use the collision to place a number. That takes longer, and it takes a quieter room.
One result of grading this way is worth knowing before you print. Clue count and difficulty do not move together. A hard sudoku does not get its difficulty from having fewer numbers on the page. North Star is in the hard group and starts with 29 given numbers. Silent Night is in the medium group and starts with 28. The hard puzzle hands you one more number than the medium one and is still the harder solve by a wide margin.
Easy: five that scanning will finish
Each of these starts with 34 or 35 numbers already placed, and each one surrenders to scanning alone. The easy Christmas sudoku pages are the ones to print if you want a puzzle you can finish between the last cup of tea and bed, or one you can pick up and put down three times without losing your place.
First Snow opens the set and is a fair place to start if it has been a while since your last grid.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Candlelight starts with one of the fuller grids in the set and works well box by box. Find the box that already holds the most numbers, take the single-fit squares out of it, and the next box opens up.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
The Wreath is a scanning exercise like the rest of the group, and a good page for building the habit of checking columns as carefully as rows.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Sleigh Bells can be done in pieces. Nothing in it depends on holding a long line of reasoning, so an interruption costs you nothing.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Gingerbread closes the group and is the one to hand to someone who knows the rules but has not solved much lately.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Solvers who search for a sudoku 9x9 easy grid usually want exactly this: a full-size board, no guessing at any point, and no need for notes.
Medium: five where the scanning stops
These start with 28 or 29 clues. More to the point, every one of them will stall on you partway through, and that stall is the design rather than a flaw.
When it happens, switch methods. Pencil the candidate numbers small into the empty squares, then look for two squares in a unit that share the same two candidates, or a candidate that appears only inside one box of a row. Each page in the sudoku printable medium group carries one grid and nothing else, so there is white space to write in.
The Nutcracker opens the medium group, and it is the one to take first if you have never written candidate lists into a grid before.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Silent Night starts with 28 given numbers, one fewer than North Star over in the hard group, and it is still the easier of the two by a long way.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Frosted Window gives up a good stretch of the grid to scanning before it closes, which makes the stall feel abrupt when it arrives.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Reindeer Run is the one where it pays to check whether a candidate is locked inside a single box before you try anything more elaborate.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Mistletoe finishes the level. If it goes still on you, read your candidate lists for pairs and triples rather than starting over.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
That is the honest definition of a sudoku 9x9 medium puzzle, and these five hold to it: solvable with certainty, but not by looking alone.
Hard: five that need chains
Clue counts here run from 26 to 29, which tells you very little. What matters is that candidate work alone will not close these grids. You will get a long way with pairs and triples, then find yourself with a half-finished board and no forced move on it.
The move at that point is to follow a chain. Assume one candidate in a square, trace what it forces through the row, the column and the box, and keep going until the consequence contradicts something you already know. Then you can eliminate it. The sudoku printable hard pages are the ones worth saving for an hour when nobody needs anything from you.
The Long Night earns its name. Expect to put it down and come back to it.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Blizzard wants a well-filled candidate grid before the first chain shows itself, so write the lists out before you start hunting.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
The Last Gift is a reasonable one to leave for last, after the other four have reminded you how the chains run.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
North Star starts with 29 numbers, as many as any puzzle in this group, and it remains the clearest demonstration in the set that a full-looking grid can be the hardest one on the table.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
Twelfth Night is the last page in the download, and like the other four it can be solved without a single guess, provided you are willing to follow the chains out.
Download this puzzle as a PDF — two pages, puzzle and answer key, US Letter.
The hard five are what a sudoku 9x9 hard puzzle should be: certain from start to finish, with no guessing required anywhere, and slow.
Answer pages and printing
Every puzzle has its own answer page, printed directly behind it. This is a sudoku printable with answers for all fifteen grids, not a sample of them.
The answer pages are built to be read rather than just checked. The squares you worked out are tinted, and the numbers that were printed as clues are left plain. So when you hold the answer next to your page, you can see your own solve separated from the starting grid at a glance, and you can find the one square you got wrong without comparing all 81.
Print on plain paper. Nothing in this Christmas sudoku printable set needs cardstock or photo stock, and the artwork sits behind the grid at a weight that leaves the numbers legible on an ordinary home printer. The grids are sized for a pencil, not a fine-point pen, because at the medium and hard levels you will be writing candidate lists into empty squares and erasing most of them again.
If you want to keep the answers out of reach while you solve, print the puzzle pages first and the answer pages separately. Page by page works too, since each puzzle is self-contained.
Before you print
Pick a level and print that level. The easy five will not teach you anything new, and they are not meant to. The medium five will ask you to write in the grid. The hard five will ask you to think several steps past the square in front of you, and they will take as long as they take.
If you are looking for something for a young child instead, the holiday set of Christmas picture sudoku for kids uses a drawing in every square and has no numbers in it at all.
