Giant Sudoku Generator & Solver

Giant Sudoku Generator & Solver (16x16 and 25x25)

Ready for the ultimate mental marathon? Giant Sudoku scales the classic logic puzzle to enormous proportions, offering massive 16x16 and 25x25 grids. Using a highly optimized bitmask backtracking algorithm, this tool generates perfectly solvable, unique Giant puzzles in milliseconds. Solve them online, or print them out for hours of offline challenge.

How to Play Giant Sudoku

The core rules remain identical to Classic Sudoku, but the scale is much larger. In a 16x16 grid, you must fill every row, column, and 4x4 block with the numbers 1-16 (or letters A-P). In a 25x25 grid, you must fill every row, column, and 5x5 block with the numbers 1-25 (or letters A-Y). Because of the massive number of interacting cells, keeping track of candidates and looking for "Hidden Singles" becomes much more complex and rewarding!

Tool Features

• Play Mode: Generate custom 16x16 or 25x25 grids instantly without freezing your browser.
• Symbol Options: Choose to play using standard numbers (1-25) or toggle to Alphanumeric mode (1-9 and A-P/Y) for a more visual experience.
• Auto-Solver: Got a Giant Sudoku from a book that you can't crack? Input the given cells and let our high-speed engine find the solution.
• Print Mode: Easily generate print-optimized PDFs tailored specifically for fitting giant grids onto a single page.

Disclaimer: This page provides an independent solver and generator tool and is not affiliated with, sponsored by, or endorsed by any specific puzzle publishers or brands.