What is Fillomino?
Fillomino is a numbered-region logic puzzle. The grid starts with a few number clues, and your job is to fill every empty cell with numbers so the board breaks into connected regions.
Each region must contain exactly as many cells as the number written in it. A group of 4s must cover four cells, a group of 2s must cover two cells, and a single 1 is already a complete one-cell region.
- Fill every cell with a number.
- Cells with the same number that touch orthogonally form one region.
- The number in a region must equal the region's size.
- Two separate regions of the same size cannot touch side by side.
- The starting clues cannot be changed.
Play Fillomino online
This free Fillomino online game includes 5x5, 6x6, 7x7, 8x8, 9x9 and 10x10 grids with easy, medium and hard difficulty settings. Choose a number from the pad, click cells to fill them, and use Erase when a region needs changing.
Every generated puzzle on this page is checked by a solver before it appears. The generator looks for a single solution, because unique-solution Fillomino is the expected standard for fair logic solving.
- Easy puzzles use smaller regions and more direct deductions.
- Medium puzzles mix small clues with longer growing regions.
- Hard puzzles use larger regions and more pressure between equal numbers.
- Check highlights mistakes, Hint fills a correct region, and Solution reveals the completed grid.
Fillomino rules
The main Fillomino rule is size matching. If a cell contains 3, it belongs to a connected group of exactly three 3s. If a cell contains 6, it belongs to a connected group of exactly six 6s.
The second rule prevents ambiguity between neighbouring regions. Two completed regions with the same number may not share an edge, because touching same-number cells would merge into one larger region.
- Diagonal contact does not merge regions.
- Orthogonal contact does merge same-number cells.
- A clue number is part of its final region.
- A region may twist and bend; it does not need to be a rectangle.
- All cells must be filled when the puzzle is solved.
Fillomino strategy tips
Good Fillomino strategy starts with forced small numbers. A 1 is finished immediately, and a 2 clue can only take one neighbouring cell. When a number has limited room, mark the cells it must use before working on flexible larger regions.
Look for borders between equal values. If two 3 clues cannot belong to the same three-cell region, they must be separated by other numbers. This no-touch rule is often the fastest way to break a crowded section open.
- Finish 1s and constrained 2s first.
- Count how many cells each clue can still reach.
- Separate same-number regions that would become too large if they touched.
- Use nearby clues to block impossible growth paths.
- When stuck, ask which empty cells can still complete each unfinished region.
Fillomino grid sizes and difficulty
Small 5x5 Fillomino puzzles are ideal for learning the rules. A 6x6 board gives a friendly daily challenge, while 7x7, 8x8, 9x9 and 10x10 Fillomino puzzles create more room for winding regions and careful separation.
Difficulty changes more than the grid size. Easy puzzles favour direct growth, medium puzzles ask you to compare several possible regions, and hard puzzles lean on chained deductions where one region's size forces several neighbours.
- 5x5 Fillomino is a quick warm-up.
- 6x6 Fillomino is a balanced beginner-friendly size.
- 7x7 Fillomino adds more region interaction.
- 8x8 Fillomino is a roomier challenge.
- 9x9 and 10x10 Fillomino add the largest boards on this page.
- All sizes and difficulties are generated as single-solution puzzles.