A LITTLE FOCUS. A FRESH START.
Play Hyper Sudoku (Windoku)
Play Hyper Sudoku, also known as Windoku, free online. Four extra shaded regions add new deductions to the classic 9×9 Sudoku grid.
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LEARN THE TWIST
How to play Hyper Sudoku (Windoku)
Hyper keeps all nine ordinary boxes and adds four shaded 3×3 regions. Jigsaw instead replaces the ordinary boxes with irregular regions.
The rules
Fill each row, column, and 3×3 box with 1–9, without repeats. Each of the four shaded 3×3 regions also contains 1–9 without repeats. Also called Windoku.
A useful first move
Focus on intersections between shaded regions and regular boxes. A candidate eliminated in one region can unlock a placement in another.
If a shaded 3×3 region already has an 8, none of its other eight cells can be 8. This remains true when those cells fall in different ordinary boxes.
SOLVE IT STEP BY STEP
Carry a restriction across an ordinary box boundary
Hyper keeps the usual boxes and adds four shaded 3×3 regions. Each shaded region needs 1–9 too. The overlap gives a number more influence: it can rule out a candidate in a cell that lies in a different ordinary box.
- Highlighted cell
- 2
Find the shared shaded region.
Both marked cells lie in the Hyper region spanning rows 2–4 and columns 2–4. The thick ordinary box lines do not divide this extra region.
Apply its no-repeat rule.
The 8 at row 2, column 2 excludes 8 everywhere else in this shaded region. It therefore removes 8 from the highlighted cell.
Use the surviving candidate.
The highlighted cell must be 2. Update its row, column, ordinary box, and shaded Hyper region; all four units must still contain different digits.
Track overlaps instead of treating regions separately
When every possible place for a digit in a shaded region lies in one row, that digit is locked into the row. It can be removed from the rest of that row outside the shaded region. The same idea works when the shared area is a column or an ordinary box.
Common mistakes to avoid
- The shaded regions are additional. Every ordinary 3×3 box still needs all nine digits.
- A cell outside the shading is not restricted by a Hyper region simply because it is nearby.
Try the reasoning yourself
Can a shaded Hyper region and an ordinary box each contain the same digit?
Show the answer and why
Yes. Each unit needs that digit once. If their placements happen to be the same cell in the overlap, one placement satisfies both. If they are different cells, those cells must still obey every unit they share.
Controls, difficulty, and saved games
Choose Beginner, Easy, Medium, Hard, or Expert above. Select an empty cell, then tap a number or use your keyboard. Notes let you pencil in candidates; three hints are available. Three mistakes end the puzzle.
Every mode and difficulty keeps a separate save in this browser. You can switch puzzles and return to your place. Clearing site data removes these saves; they do not sync with another device or the iPhone app. Settings include night mode and optional automatic cell advancement.
Correct entries earn points. High scores are stored by mode and difficulty and update only when beaten; completed-puzzle count and day streak are shared.
FIFTEEN WAYS TO PLAY
Explore all Sudoku modes
A familiar grid, a different kind of logic. Every mode is free to play in your browser.