Use even lighting
Shadows and folded pages can hide dotted cage boundaries.
Free tool / Für Papier-Sudokus
Killer-Sudoku-Löser
Photograph the complete puzzle, review its cage sums and cells, then request a hint or reveal the verified grid.
Scan puzzle
Keep every cage boundary and sum visible
Take a straight-on photo in even light. Small cage totals must remain sharp enough to read.
Recognized puzzle
Check digits, cages and sums
Bereit
Scan a puzzle or build it manually.
Every cage needs a sum and a list of cells.
Paper photo tips
Cage borders matter as much as digits.
Review every cage
Confirm the target sum and cell list before requesting a solution.
Ask for a hint first
The solver combines ordinary Sudoku restrictions with cage sums and non-repeating digits.