Sudoku Made and maintained by Brian Hamilton and Karan Hamilton.
Brian builds the playable puzzle tools, while Karan helps test clarity, difficulty feel, and the player experience.
Playable puzzles and controls are tested in the browser for rule accuracy, usability, and a clear solving experience. See how we make and test puzzles, our editorial standards, or report a problem.
What is animal sudoku?
Animal Sudoku keeps every rule of classic sudoku and lets nine animals stand in for the digits: a cat, dog, lion, monkey, panda, fox, frog, penguin and elephant. Each goes once in every row, every column and every box. One rule runs the whole zoo, and the lion gets no special treatment.
The animals come aboard a few at a time, always in the same order. The 4×4 board is the cat, dog, lion and monkey; the panda and the fox pad in at 6×6; and the frog, penguin and elephant wait for the full 9×9. The elephant, as is traditional, arrives last, and takes up exactly as much room as everyone else. The same order gives each animal its number in the Numbers and Both views, from the cat at 1 to the elephant at 9. How the views and levels work, in this zoo and in our other 20 picture games, is on the Themed Sudoku page.
The dog here is 🐶, the same emoji as the first tile in Dog Sudoku, whose key calls it Dog Face. There it shares the board with four more dogs, from a poodle to a service dog, plus a bone, a tennis racket and ball, paw prints and a dog house, so its 4×4 deals nothing but dogs. Here it is the only one.
Can a child who can’t read play animal sudoku?
Yes, and it is what this set does best. A child can name all nine of these animals long before they can read a number, so the 4×4 board makes a real first sudoku: four animals, sixteen squares and nothing to decode. In the Pictures view the squares hold only animals.
Start on 4×4 Easy with one question for each empty square: which animal is missing from its row, its column and its box? That is a naked single, the only tool a 4×4 ever calls for. Our 4x4 Sudoku page checked every 4×4 puzzle that has one answer, and that question finishes all of them. The game then grows with the child: 6×6 when rows and boxes start to click, 9×9 when they are ready to beat you at it. Anyone new to teaching it can lean on Sudoku for Kids.
How do you solve animal sudoku? Ask where each animal can go
The second question turns the first one round. Instead of picking a square and asking which animal it is missing, pick an animal and a column that still needs it, and ask where it can go. Every copy of that animal elsewhere rules out the squares in its own row and box. When the column is down to one square, the animal goes in it, even if that square could hold other animals too. That is a hidden single. The Themed Sudoku page draws one inside a box; this pair shows one down a column, on a real 4×4 Medium board from this game.
In the first picture the two questions part company. Ask which animal is missing from R1C4 and you get two answers, the cat or the monkey; ask where the monkey can go in column 4 and you get one. In the second, the monkey takes one of the cat’s two squares, and then the column finishes itself: R3C4 is the only square left, and the dog the only animal column 4 still needs.
We dealt 1,000 boards from this game’s generator, 100 per size and level up to 9×9 Medium, and tried each question alone. Where can this animal go? (hidden singles, in any row, column or box) finished every 4×4, 6×6 and 9×9 Easy board, and 94 of 100 at 9×9 Medium. Which animal is missing? finished every 4×4 and every 6×6 up to Hard, but 85 of 100 at 6×6 Expert, 98 at 9×9 Easy and only 49 at 9×9 Medium. Together, the two finished all 1,000.
Is it the cat or the fox?
We put all nine side by side in phone-sized screenshots from Chrome on Windows, every size, both themes. Four of the animals have a colour no other tile shares: the black-and-white panda, the green frog, the purple penguin and the grey elephant. The other five are warm orange and brown faces, and the pair that comes closest is the cat and the fox: both orange, both with pointed ears. The cat is yellower and has whiskers, the fox is redder with a white muzzle, and at about 21 pixels across on a 9×9 phone board, that is not much to go on. They first meet on 6×6, the size you see when the game loads.
The four on the 4×4 board, the cat, dog, lion and monkey, are warm faces too, but each has something the others lack (whiskers, a tongue, a mane, big round ears), and on 4×4 they are drawn larger. Other phones draw their own versions of each emoji. If the cat and the fox still swap places in someone’s head, switch to Both: every tile gets its number, and the cat is a 1 where the fox is a 6.
Is there a harder animal sudoku?
Yes: the 9×9 Hard and Expert boards. They start with fewer animals than Easy and Medium and can need more than the two questions above, so keep pencil marks there; the Themed Sudoku page says which steps each level is built to need. For older animals, Dinosaur Sudoku has a T-Rex, a sauropod and the world they lived in. Emoji Sudoku is a 9×9 with nine emoji and one animal among them, a butterfly. And when the pictures stop mattering, 6x6 Sudoku is the middle board in plain numbers.