About GridPaw
GridPaw is a free collection of Japanese logic puzzles — every one of them themed around cats, and every one of them solvable by pure logic alone.
What You'll Find Here
GridPaw started with Shikaku — a rectangle-division puzzle where you carve a grid into boxes, each cat marking the corner of exactly one rectangle. From there the collection grew into a full family of grid puzzles, all playable in your browser with no download and no account required:
- Shikaku — divide the grid into rectangles; every cat sits in exactly one box
- Akari (Light Up) — place cats so every cell is lit, obeying the numbered walls
- Kakuro — the cross-sum puzzle: digits that add up, crossword-style
- Nonogram — reveal a hidden picture from row and column clues
- Nurikabe — carve islands of the right size and wall off the rest
- Pictomino — a stand-alone picture-logic sub-site
- Plus KenKen, Star Battle, Takuzu (Binary), Hashi, Slitherlink, and more — the collection keeps growing
Why Cats?
Because abstract grids are friendlier with faces on them. A bulb becomes a glowing cat. A region marker becomes a sleeping cat. The logic underneath is exactly as demanding as the classic paper versions — the cats just make the hours feel warmer. If you've ever bounced off a stern, monochrome puzzle app, GridPaw is the same discipline with a softer coat.
Every Puzzle Is Solvable by Logic Alone
Every puzzle on GridPaw is generated by a solver-verified generator and has exactly one solution reachable without guessing. If you're stuck, you've missed a read — not a lucky coin flip. The built-in solver can walk you through any board step by step, and every game has its own help pages and tips hubs.
Free, and It Stays That Way
GridPaw is free to play, with no account required — all game progress stays in your browser unless you choose to sign in with Google to sync it. See the privacy policy for exactly what is and isn't stored. The site is supported by a Chrome extension and, going forward, unobtrusive advertising.
Who Builds GridPaw
GridPaw is built and maintained by an independent developer who has loved Japanese logic puzzles for years and kept sketching cat doodles in the margins. New puzzles, difficulty tiers, and quality-of-life features ship continuously — the changelog tracks every update.
Get in Touch
Found a bug, want a new puzzle type, or just want to say the cats made your commute better? The contact page has the details. Messages are read by a human — usually the same one who drew the cats.
FAQ
Is GridPaw really free?
Yes. Every puzzle, every difficulty tier, every help page — free, no account required. Progress saves in your browser automatically.
Do I need to create an account?
No. You can play everything anonymously. An optional Google sign-in exists only to sync your progress across devices.
Are the puzzles original?
Yes. Every board is generated on the fly by GridPaw's own solver-verified generators, with a unique solution reachable by logic alone. The puzzle types themselves (Shikaku, Akari, Kakuro, and friends) are classic Japanese designs, several popularized by the publisher Nikoli.
Can I use GridPaw puzzles in my classroom or publication?
Get in touch via the contact page and describe what you have in mind — classroom use is usually an easy yes.