Sudoku generator

Generate a fresh Sudoku puzzle — easy, normal, or hard — with a unique solution you can reveal or print.

Difficulty

Generated in this browser. Nothing is sent anywhere.

A random completed grid is dug into a symmetric puzzle while a backtracking solver proves the solution stays unique. Digits are fixed — the puzzle cannot be filled in on this page; print it or copy the grid.

How to use

  1. Pick a difficulty.
  2. Generate the puzzle.
  3. Solve it on screen, show the solution, or print it.

What it supports

Seeded backtracking generator with symmetric clue removal; uniqueness is verified by a solver. Hard puzzles take a moment longer to build. Generation happens locally — no two puzzles are guaranteed different, though repeats are very unlikely.

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