Play 16x16 Mega 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 completed grid.

Advanced 16x16 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.