Sudoku Solver with Steps
Enter a Sudoku (type it, paste it, or upload a photo) and solve it the way a person would: one move at a time, easiest technique first, each step explained by the same coach that gives hints in Funzzle's Daily Sudoku. Step back and forward, or jump to any move.
Paste a puzzle as text
Current grid: .................................................................................
Rather solve one yourself? The Daily Sudoku has the same coach built in: ask for a hint and it points you to the next step without giving the answer away.
How to enter a puzzle
Tap a square and type a digit; the cursor moves on to the next square, and the arrow keys move around. Leave empty squares blank. To paste a puzzle, open "Paste a puzzle as text" and paste 81 characters row by row, with 0 or a dot for each blank.
To use a photo, take it straight on in good light, cropped to the grid if you can, and upload it. The solver finds the grid, reads each digit on your device, and fills the board. Photo reading is a first draft: check every number against your puzzle and fix any it misread before you press Solve.
What the steps mean
The solver always tries the simplest technique first. Naked singles (a square with only one possible number) and hidden singles (a number with only one possible square in a row, column or box) solve most easy and medium puzzles. Harder puzzles need eliminations: pointing and claiming, naked and hidden pairs and triples, and for the hardest grids X-Wing, Swordfish and XY-Wing. Each step says where to look, why the move works, and what it changes.
If a puzzle needs more than those techniques, the solver says so and fills in the rest from the unique solution. If the grid has a repeated number, no solution, or more than one solution, it tells you instead of guessing.
Questions people ask
Does it solve any Sudoku?
Any valid 9×9 Sudoku. It explains every step it can with its eleven techniques; the very hardest puzzles may need a few cells of trial and error at the end, and the solver tells you when that happens.
Can I solve a Sudoku from a photo?
Yes: tap Upload a photo. Digits are read in your browser (nothing is uploaded to a server), then shown on the board for you to check before solving.
Why does it say my puzzle has more than one solution?
A proper Sudoku has exactly one solution, which needs at least 17 given numbers. If a number is missing or mistyped there may be several, and no logical path to explain.
Can I get a hint instead of the whole solution?
Press Next step once and stop: the first step shows where to look and why. In the Daily Sudoku the coach's hints go in three stages, from a nudge to the answer.