Cleared a level? Leave a note for the other detectives.
Start with prime numbers — their 1×N shape is forced — then work from corners and the largest clues. Each rectangle's area must match its number exactly, and forced placements come first.
3×3 grids with guided hints. Learn rectangle placement, area rules, and elimination basics.
5×5 grids with simple shapes. Practice prime numbers and corner strategies at your own pace.
5×6 grids with complex shapes. Master prime numbers, corner strategies, and multi-step deduction.
6×6 grids. Combine multiple techniques and plan several moves ahead.
7×8 grids requiring deep reasoning. Chain eliminations, overlap detection, and forced placements.
10×10 puzzle seeded by date. Same puzzle worldwide — compare your time with friends.
From Tutorial 3×3 to Legend 8×8 — every puzzle has a unique logic-only solution.
Play GridPaw anywhere, anytime. Add to your home screen for offline support, no browser bars, and instant launch.
GridPaw is a free Shikaku puzzle game with adorable cat visuals. Draw rectangles on a numbered grid so each rectangle covers exactly the number of cells shown. It's the classic Shikaku (rectangle partition) puzzle by Nikoli — the same company behind Sudoku — reimagined with cats.
Whether you're new to Shikaku or a seasoned solver, GridPaw offers unlimited procedurally generated puzzles across 7 difficulty levels, from Tutorial 3×3 to Legend 8×8. Every puzzle has a unique solution reachable by pure logic — no guessing required.
The rules of Shikaku are simple:
That's it — no math beyond multiplication. The challenge is figuring out which shapes fit where when multiple numbers compete for space.
Unlike many puzzle sites, GridPaw has no ads during gameplay, no paywalls, and no registration. Every puzzle is free, every solution is unique, and every solve ends with a cute cat celebration. The Daily Challenge gives you a reason to come back every day with a fresh 6×6 puzzle and streak tracking.
If you enjoy Sudoku, KenKen, or other logic puzzles, Shikaku offers a refreshing change with spatial reasoning instead of arithmetic. The rectangle partition mechanic is easy to learn but rewards deep thinking — perfect for a coffee break or a long session.
Shikaku 
Akari 
Kakuro 
Nonogram 
Nurikabe 
Pictomino