How do you solve a Mosaic puzzle?

Start with the easiest clues: a 0 means every cell in its neighbourhood must be empty, and a clue equal to its neighbourhood size (e.g. 9 for an interior cell) means every cell must be filled. Then look for clues where the number of unknown cells equals the remaining count, forcing those cells to be filled or empty. Cross-reference overlapping neighbourhoods to deduce further.

What grid sizes are available?

Three sizes: 5×5 (quick puzzles for beginners), 7×7 (a balanced challenge), and 10×10 (larger grids for experienced solvers wanting a longer session).

What difficulty levels are there?

Three levels: Easy (many numbered clues and straightforward deductions), Medium (fewer clues requiring more cross-referencing), and Hard (minimal clues demanding deep logical reasoning and overlapping-neighbourhood analysis). All puzzles have a unique solution solvable with logic alone.

Is Mosaic the same as Minesweeper?

They are related but different. In Minesweeper, mines are hidden and you reveal numbers by clicking—one wrong click loses the game. In Mosaic, all clue numbers are visible from the start and you never have to guess. Mosaic is a pure logic puzzle with a guaranteed unique solution.

Play Mosaic Puzzle Online

Q: What is a Mosaic puzzle?

A Mosaic puzzle (also called Fill-a-Pix or Mosaic Logic Puzzle) is a grid-based logic puzzle. Some cells contain a number from 0 to 9 that tells you exactly how many cells in its 3×3 neighbourhood (the cell itself plus all orthogonal and diagonal neighbours) must be filled (shaded). Your goal is to determine which cells are filled and which are empty using logic alone.

Shade cells so every numbered clue matches the count of filled cells in its 3×3 neighbourhood. Pure logic — no guessing required!

Filled

Time

0:00

Tap to fill — tap again to mark empty — tap once more to clear

What Is a Mosaic Puzzle?

A Mosaic puzzle — also known as Fill-a-Pix, Mosaic Logic Puzzle, or simply Mosaic — is a grid-based logic puzzle that shares a visual kinship with Minesweeper but plays very differently. The grid begins with some cells containing a number between 0 and 9. Each number tells you exactly how many cells in its 3×3 neighbourhood (the cell itself plus all orthogonal and diagonal neighbours) must be filled (shaded black). Your job is to determine, using logic alone, which cells are filled and which are empty.

Unlike Minesweeper, every clue is visible from the start and every puzzle has a unique solution that can be reached without guessing. The interplay of overlapping neighbourhoods is what makes Mosaic puzzles online such a satisfying deduction challenge.

Rules of Mosaic

Neighbourhood count: Each numbered cell indicates exactly how many of the cells in its 3×3 area (itself plus up to 8 neighbours) are filled.
Fill or leave empty: Every cell in the grid must be either filled (shaded) or empty (white). There is no third state in the solution.
Corners and edges: Cells on the border or in a corner have smaller neighbourhoods (6 or 4 cells instead of 9), so their clue numbers reflect that reduced count.
Unique solution: A well-formed Mosaic puzzle has exactly one valid solution, reachable through pure logical deduction with no guessing.

How to Solve Mosaic Puzzles

1. Start with Zeroes and Maxes

A 0 clue means every cell in its neighbourhood must be empty — mark them all as empty immediately. Conversely, a clue equal to the neighbourhood size (e.g. 9 for a centre cell, 6 for an edge cell, or 4 for a corner cell) means every cell in that neighbourhood must be filled.

2. Count Known Cells

For each clue, count how many cells in its neighbourhood are already known (filled or empty). If the number of remaining unknown cells equals the number of fills still needed, all unknowns must be filled. If the clue is already satisfied, all remaining unknowns must be empty.

3. Cross-Reference Overlapping Clues

Two adjacent clues share part of their neighbourhoods. If filling or emptying a cell would make one clue impossible, that cell’s state is forced by the other clue. This cross-referencing is the core technique for solving Mosaic puzzles at higher difficulties.

4. Work from Edges and Corners

Clues near the border have smaller neighbourhoods, which means fewer unknowns and easier deductions. Start from the edges and work inward. Corner clues with a neighbourhood of just 4 cells are especially informative.

5. Eliminate Impossibilities

If assuming a cell is filled leads to a contradiction (another clue would exceed its count), the cell must be empty — and vice versa. This “what-if” reasoning is sometimes needed on harder puzzles.

6. Use the Remaining Count

The info strip above the grid tracks how many cells you have filled so far. On harder difficulties, comparing your filled count against what the clues imply can provide a useful sanity check.

Grid Sizes & Difficulty Levels

5×5 — Easy: Compact grid with plenty of clues. Perfect for learning the rules and basic techniques of Mosaic puzzles.
5×5 — Medium/Hard: Same small grid but fewer clues, requiring more cross-referencing between overlapping neighbourhoods.
7×7: The sweet spot for most solvers. Enough room for interesting deduction chains without overwhelming complexity.
10×10: Large grids for experienced Mosaic fans. Longer solve times and deeper neighbourhood-overlap interactions.

Mosaic vs Other Logic Puzzles

vs Minesweeper: Both use numbered clues about neighbours, but Minesweeper hides clues under cells and involves risk. Mosaic shows all clues up front — it is a pure logic puzzle with no luck.
vs Nonograms: Both reveal a shaded picture, but Nonograms use row/column run-length clues while Mosaic uses local 3×3 neighbourhood counts.
vs Nurikabe: Both involve shading cells, but Nurikabe requires a connected sea and isolated islands, while Mosaic has no connectivity constraints — only local counts.
vs Light Up: Both have numbered wall/clue cells constraining neighbours, but Light Up places objects (bulbs) that illuminate entire rows/columns, while Mosaic clues are strictly local.

Tips for Faster Solving

Mark empties early: Confirming empty cells is just as valuable as finding filled ones — it reduces unknowns for every overlapping clue.
Scan for forced cells: After each move, quickly scan adjacent clues to see if anything new is forced. Chain reactions are common.
Use the check button: If you are stuck, tap Check to see if any placed cells conflict with a clue.

Frequently Asked Questions

A Mosaic puzzle is a grid-based logic puzzle where numbered cells tell you how many of the surrounding cells (including the numbered cell itself) should be filled. It is also known as Fill-a-Pix.

Start with clues of 0 (mark all neighbours empty) and clues equal to their neighbourhood size (fill all neighbours). Then count known cells around each clue and cross-reference overlapping neighbourhoods to deduce the rest.

Three sizes: 5×5 for quick games, 7×7 for the classic experience, and 10×10 for a bigger challenge.

Easy (many clues, straightforward deductions), Medium (fewer clues, more cross-referencing), and Hard (minimal clues requiring deep logical reasoning). Every puzzle has a unique solution.

They are related but different. Minesweeper hides mines and involves chance — one wrong click ends the game. Mosaic shows all clue numbers from the start and is a pure logic puzzle with a guaranteed unique solution and no guessing.

More Puzzle & Strategy Games

If you enjoy Mosaic, try these other free games on our site:

Minesweeper

The classic mine-finding game with numbered neighbourhood clues.

Nonograms

Reveal pixel art by filling rows and columns based on run-length clues.