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16×16 sudoku
A 16×16 sudoku (mega / hexadoku-style) fills a 16-by-16 grid so each row, column, and 4×4 box contains each symbol once. This page plays that size in the browser: digits 1–9 display as numbers, 10–16 as A–G.
Generation keeps a unique solution. Hint focuses on naked and hidden singles so coaching stays fair on a dense grid. Check marks conflicts only — it will not dump the whole answer.
When
When to use
You searched 16×16 / mega sudoku; you want a real mega board, not a shrunk 9×9.
When not
When not to
Normal 9×9 fight → hard / expert. Samurai overlaps → samurai sudoku. Mini sizes → mini sudoku.
Defaults
Assumptions
Playable board is 16×16 with 4×4 boxes and symbols 1–16 (shown as 1–9, A–G). Unique solution. Progress stays in this browser.
Steps
How
- Scan a 4×4 box the way you would a 3×3 — sixteen cells, sixteen symbols.
- Use the pad or keys 1–9 and A–G; Pencil stores candidates the same way.
- Hint names a single when one exists; denser fish techniques stay on classic 9×9 pages.
- New puzzle regenerates a unique mega grid on this URL.
Worked notes
Examples
- Looking at a mega box → box is 4×4, not 3×3 — sixteen cells per house
- Letter F on the pad → means symbol 15 — no math meaning, just a label
Watch-outs
Gotchas
- Printable 16×16 PDFs are not this page.
- Hints stay on singles so a dense board still coaches fairly.
- Diagonals are optional elsewhere — not assumed on this URL.
Nearby pages
Compare
Samurai: samurai sudokuExpert classic: expert sudokuStrategy: sudoku strategyPlay: play sudoku
Controls
Quick controls
- Hint — a cell/digit, technique name, and short reason.
- Check — flags conflicts without revealing the full grid.
- Pencil — candidate notes for empty cells.
- New puzzle — same difficulty band, fresh seed.
- Daily — fixed local seed for the calendar day.
- Erase — clear the selected cell (not givens).
FAQ
Common questions
Is 16×16 playable today?
Yes. The live board is a true 16×16 with unique generation, conflict check, and singles-based hints.
Numbers or letters?
Internal values are 1–16. The UI shows 1–9 and A–G for 10–16. Each symbol still appears once per house.
Harder than evil 9×9?
Different shape and longer sessions. Evil 9×9 stays on the evil sudoku page.
Do I need an account?
No signup. Progress stays in this browser’s local storage.