Our free sudoku generator creates unique puzzles using a backtracking algorithm — the same method used in professional puzzle books.
Every puzzle is generated fresh in your browser, so no two downloads are the same.
Puzzles are formatted for US Letter (8.5" × 11") paper with large, clear numbers perfect for printing.
The answer key page uses red numbers to clearly distinguish filled-in answers from given clues.
Ideal for elementary Klassenraums, after-school programs, senior centers, and Heimunterricht families.