Play Fillomino Online
Divide the grid into polyominoes matching their own numbers.
How to Play Fillomino
Modes: Easy · Medium · Hard · Daily
Fillomino asks you to divide the grid into connected regions, then write a number in every empty cell.
Every cell in a region shows the same number, and that number equals how many cells the region contains.
Select a cell and tap a number from the pad. Given numbers are locked and blue.
Regions with the same size may never touch each other side by side.
Rules
A region is an orthogonally connected group of cells sharing the same number.
The number in a region equals exactly its number of cells.
Two different regions never touch if they share the same number.
The whole grid is covered by regions.
Scoring
| Solved | fill every cell with its region size |
| Time | fastest solve wins |
History & Origins of Fillomino
Fillomino is a division puzzle from the Nikoli stable, the Japanese publisher that also carried the name Sudoku to the wider world. It first appeared in Nikoli’s magazine around 1994 and soon earned a reputation as one of the purest region-splitting formats ever printed. The title itself fuses ’fill’ with ’polyomino’, hinting at the connected blocks a solver is expected to build.
Unusually, the clues do not tell you where things go; they describe what each finished area must look like. A printed number states the exact size of the connected block that holds it, and two same-number blocks may never sit side by side, because touching equal regions would quietly merge into one oversized piece that no longer matches either clue.
That tension between growing regions and stopping them in time is the whole game: every digit is at once a target and a guardrail. Each empty cell must eventually carry the size of its own region, so solvers think about containment before writing anything. ThinkyPlay scales the challenge from quick 6x6 grids up to denser 8x8 boards for a longer stretch.
While Nikoli printed the format in ink, its rules were made for the screen too: no hidden words, no arithmetic beyond counting, just a map of walls that appears only in the solver’s head. That clean design is why Fillomino keeps showing up in puzzle anthologies and mobile logic collections long after its magazine debut.
Common Mistakes to Avoid
- Placing two equal numbers in touching cells when you mean separate regions, forgetting that adjacent same values silently merge into one region.
- Judging a region’s size from its given clues alone, while forgetting that the blank cells around them also belong to the region and must be filled.
- Letting a connected group grow past its number and ignoring the ’Too many together’ warning instead of trimming the region back.
- Building walls that trap a pocket of cells too small to hold any remaining region size, which quietly makes the grid impossible to finish.
Tips & Strategy
Start from big given numbers and grow their regions until they reach the right size.
A number surrounded on all sides except one forces its region to extend that way.
When a region reaches its size, wall it off — no neighbour can share its number.
Cells trapped between completed regions often have only one possible number left.
Use the Hint button when stuck; it fills one correct cell.
Frequently Asked Questions
- Is Fillomino free to play?
- Yes — Fillomino on ThinkyPlay is completely free, with no download and no sign-up.
- What do the numbers mean?
- A number is the size of its region: a 3 means that connected group has exactly three cells, all labelled 3.
- Can two regions with the same number touch?
- No — if two equal numbers touch, they must actually be the same region.
- Are all puzzles solvable?
- Yes — every puzzle has exactly one solution, and the Hint button fills one correct cell.
- What does the ’Too many together’ warning mean?
- It flags a connected group whose cells already outnumber the value they share. Equal neighbours count as one region, so trim the group back until its size matches its number again.
- How do the difficulty levels change Fillomino?
- Easy plays on a 6x6 grid, Medium moves up to 7x7, and Hard fills an 8x8 board. Bigger grids hold more regions with larger areas, so keeping the whole wall map in your head gets noticeably tougher.
- Is there a daily Fillomino puzzle?
- Yes. Every day all players receive the same Medium 7x7 board, and your best time for that day’s puzzle is stored under its own daily record.