Hyper Sudoku 6×6 Hard — Set 99
Solver Notes
Hard 6x6 Hyper with the shifted constraint regions at full intensity. Requires active re-mapping of constraint overlaps. 8-14 minutes.
Hyper Sudoku — Free Online & Printable
Hyper Sudoku is closely related to Windoku but places its four extra regions in slightly different positions. Like Windoku, it adds four 3x3 areas that must each contain digits 1-9, but the region placement creates different solving patterns. The name "Hyper" reflects the elevated difficulty that these particular window positions create — the constraints interact in ways that require careful cross-region reasoning. Hyper Sudoku puzzles at the same difficulty rating as Windoku often feel harder, making it a good progression challenge after mastering Windoku.
About 6x6 Grid
The 6x6 grid strikes a balance between accessibility and depth. With 36 cells in 2x3 boxes, puzzles take 3 to 10 minutes depending on difficulty. The 6x6 is large enough to showcase variant rules meaningfully — Killer cages have room to create genuine arithmetic puzzles, Windoku windows overlap in interesting ways — while remaining completable in a single sitting. Many players find the 6x6 their "daily driver" format: challenging enough to be satisfying, short enough to fit into a break.
Hard Difficulty
Hard difficulty introduces multi-step deductions where you must track constraint chains across multiple regions simultaneously. Required techniques include naked pairs/triples (two or three cells sharing the same possible values), pointing pairs (where a candidate is confined to one row or column within a region), and intersection removal. For variant-specific techniques: Killer Hard requires cage combination analysis where several possibilities exist and must be eliminated systematically. Average time: 20-40 minutes for 9x9.
How to Get Started
- Choose "New Puzzle" to generate a fresh puzzle with a unique solution
- Click or tap cells to enter numbers (1-6 for 6x6)
- Use the constraint highlights to track which numbers are still available
- Print the puzzle if you prefer solving on paper