How to Play Mega Sudoku
Mega Sudoku — also known as Super Sudoku or Sudoku 16 — scales the classic puzzle up to a 16x16 grid of 256 cells, divided into sixteen 4x4 boxes. Fill every cell with a number from 1 to 16 so that each row, each column, and each 4x4 box contains every number exactly once. The logic is identical to classic Sudoku; the challenge is stamina and bookkeeping. Every puzzle here is pre-generated and verified to have exactly one solution.
- Daily Mega Sudoku: One shared 16x16 puzzle per difficulty per day — the same grid for everyone, refreshed at midnight.
- Entering 10–16: Use the on-screen pad, or on a keyboard press A–G for 10–16 (A=10 … G=16). Digits 1–9 work as usual.
- Notes: Toggle Notes (or press N) for pencil marks — on a grid this size, they're not optional!
- Error checking: Wrong numbers turn red instantly, so a small slip can't silently ruin an hour of work.
- Difficulty: Easy gives about 150 starting numbers, Medium about 130, Hard about 112. New to the giant grid? Start Easy — it's a full workout already.
Strategy on the Giant Grid
All classic techniques transfer directly: scan each number across the boxes it's missing from, hunt naked and hidden singles, and lean on pencil marks far earlier than you would on a 9x9. Because each number appears 16 times, cross-hatching passes are longer — work box by box in a fixed order so you never lose your place. The complete strategy walkthrough is in our Mega Sudoku 16x16 guide, and the general toolbox lives in the solving techniques library.
Frequently Asked Questions
How long does a 16x16 Sudoku take?
Plan for 30 minutes to 2 hours depending on difficulty and experience — roughly three to four times a comparable 9x9. The timer runs while you solve, and your board stays put as long as the page is open.
How do I type numbers above 9?
Keyboard players use the letter keys A through G for 10 through 16; the on-screen pad simply shows all sixteen numbers. Cells display the numbers 1–16 directly, so there's no letter-code to memorize while reading the grid.
Is Mega Sudoku harder than regular Sudoku?
The deductions are the same difficulty per step — there are just far more of them, and more candidates per cell (up to 16). It rewards tidy, systematic solving over flashes of insight, which is exactly why fans love it. If you're new to Sudoku entirely, warm up with the daily 9x9 first.
Can I play on my phone?
Yes — though 256 cells on a phone screen is cozy. A tablet or desktop is roomier, and the free Sudoku - Brain Puzzles app for iPhone and iPad plays Mega 16x16 with pinch-zoom, auto-saving, and smart hints that explain the next logical step.