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Tap a cell to cycle: shaded sea • dotted land • empty · ✔ Check is free · 💡 3 hints per puzzle
Nurikabe is a shading puzzle with four short rules and a deep well of logic. Shade cells to build one single sea. Leave the rest as islands. Every island must hold exactly one printed number, and the island must end with exactly that many cells. No guessing is ever needed. Every puzzle here has exactly one solution, and this page gives you 40 set puzzles in four sizes plus a fresh Daily Nurikabe every day.
New to shading puzzles? Start on the 6×6 Starter tier. The first puzzles teach you the whole game in a few minutes. Then climb to 7×7, 8×8 and the full 9×9 Expert grid.
🧩 Logic📅 Daily Puzzle🆓 Free📱 Mobile Friendly🌊 One Sea
🌊 One Sea
Every shaded cell must join one single connected sea. No shaded cell may be cut off on its own.
🏝️ True Islands
Each island holds one number and exactly that many cells. A 6 needs an island of 6 white cells, no more, no less.
🚫 No 2×2 Sea
The sea may never form a solid 2×2 block. That one rule keeps every sea winding and every puzzle honest.
✔ Check and Hints
A free Check button counts broken rules by type, and 3 hints per puzzle set one wrong cell right. Clean solves earn 3 stars.
In this guide
- How to play Nurikabe
- The four rules, one by one
- The sizes on GameOLL
- Solving strategies that actually work
- The Daily Nurikabe and your streak
- Stars, Check and hints
- 7 tips for faster solves
- Frequently asked questions
How to play Nurikabe
Tap any plain cell. The first tap shades it as sea. Tap again and it becomes a dot, your mark for a cell that must stay land. Tap a third time and the cell clears. Numbered cells are printed on the board. They never change, and each one is the seed of an island.
Nothing is enforced while you tap, so you are free to explore. When you want a verdict, press ✔ Check. Check reads your shaded cells as sea and your dots as claimed land, then counts every broken rule by type. It never marks which cells are wrong. Finding them is the game.
| Step | What to do |
|---|---|
| 1 | Pick a puzzle, or tap 📅 Daily for today’s grid. |
| 2 | Tap cells to shade the sea. Tap again to dot sure land. |
| 3 | Grow each number into an island of exactly its size. |
| 4 | Keep islands apart, keep the sea joined, dodge 2×2 blocks. |
| 5 | Press ✔ Check to count broken rules, 💡 Hint when stuck. |
| 6 | Shade the last sea cell correctly and the puzzle completes. |
The four rules, one by one
Rule one: the sea is one. All shaded cells must connect into a single region, moving up, down, left and right. A shaded cell stranded on its own breaks the rule, even at the very end of a solve.
Rule two: every island is true to its number. An island is a group of white cells joined side by side. It must contain exactly one printed number, and its cell count must match that number exactly. An island of 7 cells around a 5 is just as wrong as an island of 3.
Rule three: islands never touch side by side. Two different islands may not share an edge, because then they would be one island with two numbers. Touching at a corner is fine. In fact, the thin sea walls between islands usually run diagonally for this reason.
Rule four: the sea never forms a solid 2×2 block. Four shaded cells in a square are banned. This is the rule that gives Nurikabe its shape: the sea has to wind and thread between the islands instead of pooling in corners.
The sizes on GameOLL
Four tiers, ten puzzles each. The grid grows, the islands grow, and the sea gets longer and thinner. Every tier is free, and your stars are saved per puzzle.
| Tier | Grid | Islands | Best for |
|---|---|---|---|
| Starter | 6×6 | 5 to 7 | Learning the four rules |
| Classic | 7×7 | 6 to 8 | The everyday solve |
| Daily | 8×8 | 10 to 13 | One fresh puzzle every day |
| Tough | 8×8 | 7 to 10 | Long seas, deep logic |
| Expert | 9×9 | 10 to 15 | The full-size challenge |
Solving strategies that actually work
Shade between two numbers first
When two numbered cells sit one step apart, the cell between them can never be land: it would join the two islands into one. Shade it. The same goes for two numbers on a diagonal with a shared neighbour cell in the corner between them. That shared cell would touch both islands, so it is sea too.
Wall off finished islands
The moment an island reaches its number, every white neighbour around it must be sea. Shade the whole ring at once. Each finished island you wall off hands you free sea cells, and those cells often complete the ring of the island next door.
Hunt the 2×2 before it forms
Whenever three cells of a 2×2 square are shaded or clearly sea, the fourth cell is land for sure. Dot it, then ask which island can claim it. This single habit cracks more Nurikabe puzzles than any other, because the no-2×2 rule reaches into almost every corner of the grid.
Grow islands from their only door
An island that still needs cells but has only one white neighbour must grow through that neighbour. Mark the path step by step. Long thin islands along an edge are usually forced this way, one cell at a time, and each forced cell can wall off the island beside it.
Keep the sea breathing
Before you shade a cell, check that the sea can still reach every corner of the grid. A shaded cell that seals a pocket of white cells away from the rest of the sea is a mistake, because that pocket could then never join the one sea. Think of the sea as water: it must always be able to flow everywhere it still needs to go.
The Daily Nurikabe and your streak
Every day brings one fresh 8×8 puzzle, built from the date itself, so every player in the world gets the same grid on the same day. Solve it to start or grow your streak. Miss a day and the streak restarts, but your stars and best times never reset.
Leave a puzzle half done and it waits for you. Your shaded sea, your dots and your remaining hints are saved in this browser and restored exactly where you left them, with a welcome-back line when you return.
Stars, Check and hints
Every set puzzle pays up to 3 stars. Finish with no hints used and no wrong Checks to earn all 3. Use one hint, or let one Check come back with problems, and the puzzle pays 2. Anything heavier pays 1, and a finished puzzle always pays at least 1.
Check is free and unlimited. It counts broken rules by type: 2×2 sea blocks, joined islands, oversized islands, stranded land and trapped islands. It never says which cells are wrong. Hints are the opposite trade: a hint sets one wrong cell right for you, and you get exactly 3 per puzzle.
7 tips for faster solves
- Shade the cell between any two numbers that sit one step apart.
- Wall off each finished island with a full ring of sea at once.
- Dot the fourth cell of every 2×2 square that has three sea cells.
- Grow islands through their only door, one forced cell at a time.
- Never shade a cell that seals white cells away from the sea.
- Stuck? Press Check before you spend a hint. It is free.
- Climb one size at a time: 6×6 teaches the rules, 9×9 tests everything.
Frequently asked questions
What is Nurikabe?
Nurikabe is a Japanese logic puzzle played on a grid. You shade cells to form one connected sea, and every unshaded island must hold exactly one printed number and exactly that many cells.
What are the rules of Nurikabe?
Four rules: the shaded cells form one connected sea; each island holds one number and exactly that many cells; islands never touch side by side; and the sea never forms a solid 2×2 block.
Does every puzzle have exactly one solution?
Yes. Every puzzle on this page, set and Daily alike, was generated and then proven by two independent solvers to have exactly one solution. If your grid obeys all four rules, it is the solution.
What does the dot mean?
Tapping a cell cycles it from empty to shaded sea to a dot and back to empty. The dot is a note that means definitely land. It locks nothing, but the Check button reads your dots as claimed land.
How does the Daily Nurikabe work?
A new 8×8 puzzle is generated from the date every day, the same for every player. Solve it to build your daily streak. Your streak, stars and best times are saved in your browser.
Can I play Nurikabe on my phone?
Yes. The game runs in your browser with no download and no sign-up. Tap cells to shade the sea, use Check and hints with touch, and the 9×9 grid is sized to fit your screen.
🏆 Final Verdict
Nurikabe is the purest shading workout on GameOLL. Four rules, zero luck, and every puzzle proven to have exactly one answer. Start with the 6×6 tier, earn your stars, keep the Daily streak alive, and take on the 9×9 Expert boards when the sea starts flowing for you.
A note on the name: Nurikabe is the Japanese shading puzzle style popularised by Nikoli. This page is an independent GameOLL implementation. Every grid, island layout and line of code here is original to GameOLL, and the puzzle format itself is a classic logic format anyone may implement.
Last updated: November 8, 2026
