Nurikabe
Shade the sea so every number gets its island.
About Nurikabe
Nurikabe is a Japanese logic puzzle about islands in a sea. Numbers give the size of each island, and the shaded sea must flow around them in one piece. Every puzzle here has exactly one solution.
How to play
Shade cells to make one connected sea. Each number belongs to a white island of exactly that many cells, every island holds exactly one number, and the sea may never contain a 2×2 block of shaded cells. Mark cells you know are island with a dot.
Tips and strategies
- A cell between two numbers belongs to neither island, so it's sea.
- Once an island reaches its size, wall it off with sea.
- Three shaded cells of a 2×2 square force the fourth to be island.
Nurikabe strategy guide
Finish islands of 1 at once by shading every cell around them. Then shade any cell that touches two different numbered islands, because islands may never merge.
Shade the cells no island can reach. An island of 3 extends at most two steps from its number, so a cell too far from every number must be sea.
Avoid 2×2 pools. When three cells of a 2×2 block are already sea, the fourth must be white — part of an island that can still grow there.
Frequently asked questions
What are the rules of Nurikabe?
Shade cells to form one connected sea. Each number belongs to a white island of exactly that many cells, every island holds exactly one number, and the sea may never contain a 2×2 block of shaded cells.
Which sizes can I play?
5×5, 6×6 and 7×7. The daily challenge is 6×6.
Does every Nurikabe have one solution?
Yes. Each puzzle is adjusted until a solver proves that its solution is unique.
Is Nurikabe free to play?
Yes. Every game on Puzzimo is completely free and runs in your browser on desktop, tablet and phone — no download or installation.
Do I need an account?
No. You can play instantly as a guest and still appear on the leaderboards. Sign in with Google, Discord or LINE to keep your scores on every device.
How does the daily Nurikabe challenge work?
Every day at 00:00 UTC everyone gets the same new puzzle. Only your first finish of the day counts on the leaderboard.
How are leaderboard results verified?
Our servers replay every move of your game and measure the time themselves, so leaderboard results can't be faked.