Play 16x16 Sudoku

Take on a full 16x16 Sudoku grid (factor 4) with symbols 1 to 9 and A to G. This page is for advanced players who want a longer logic challenge and a stricter candidate-tracking workout.

Fill each row, column, and 4x4 box with every symbol exactly once, then click Submit Puzzle to validate your Mega Sudoku grid.

Need tools or a different grid?

Use the 16x16 Sudoku Solver to test candidates or rescue a stuck puzzle
Use the 9x9 Sudoku Solver for standard Sudoku checks
Play 9x9 Sudoku if you want a faster puzzle cycle

Advanced 16x16 Sudoku solving tips

Track symbol families. In 16x16, split candidate scanning into 1-8 and 9-G passes to reduce visual overload.
Prioritize constrained boxes. A nearly complete 4x4 box often unlocks multiple row and column placements quickly.
Use cross-hatching aggressively. Eliminate candidates by intersecting row, column, and box constraints before committing a value.
Stabilize before submitting. A final full-grid sweep for duplicate symbols catches most late-stage mistakes.