How to Win at Daily Mosaic: Strategy Guide

Daily Mosaic is a logic puzzle inspired by the classic Fill-a-Pix. Each number in the grid tells you exactly how many of the surrounding squares — including the numbered square itself — must be shaded. Deduce them all correctly and a hidden pixel art image emerges. No guessing required.

How the Numbers Work

Every clue number controls a neighbourhood of up to nine cells: the clue cell itself, four directly adjacent cells (up, down, left, right), and four diagonal cells. The number tells you exactly how many of those nine cells are shaded. A clue in the middle of the board has nine neighbours. A clue on an edge has six. A clue in a corner has only four.

That shrinking neighbourhood at the edges and corners is the first thing expert solvers exploit — and it unlocks huge sections of the puzzle immediately.

Strategy 1: Start with the Absolutes

The fastest way to unlock a Mosaic puzzle is to find clues where the answer is already determined — no deduction needed. These are the freebies, and you should mark every single one of them before doing anything else.

• 0 anywhere: All cells in the neighbourhood are empty. Mark every neighbour as blank immediately.
• 9 in the interior: All nine surrounding cells are shaded. Fill them all in at once.
• 6 on an edge: An edge cell has exactly 6 neighbours. A clue of 6 means every one is shaded.
• 4 in a corner: A corner cell has exactly 4 neighbours. A clue of 4 means every one is shaded.
• 1 in a corner: A corner cell with a clue of 1 means only one of its four neighbours is shaded — but all three others are blank. Mark three blanks immediately.

Scan the entire grid for these before touching anything else. On a typical puzzle, this first pass alone resolves 20–30% of all cells.

Strategy 2: Use Edge and Corner Maths

Position on the board changes what a number means. A clue of 5 in the interior means five out of nine are shaded — still some uncertainty. But the same clue of 5 on a flat edge means five out of only six cells are shaded, and you can immediately identify which cell must be blank. The reduced neighbourhood turns moderate numbers into near-absolutes.

Work through all edge and corner clues systematically after your absolute pass. The rule is simple: if the clue value equals the neighbourhood size, shade everything. If the clue is one less than the neighbourhood size, all but one cell is shaded — and often you can determine which one is the exception from adjacent clues.

Strategy 3: The Overlapping Neighbourhood Technique

This is the core advanced technique — and the one that solves the hardest sections of the puzzle. When two adjacent clue cells share some of the same neighbours, you can cross-reference their counts to deduce cells that neither clue can solve alone.

Here's the logic: if a high-value clue (say, 6) and a low-value clue (say, 2) share four cells in common, you know that at most 2 of those shared cells are shaded (limited by the low clue). That means the high clue's remaining cells — the ones it does not share with the low clue — must account for the rest of its required shading. Work out the arithmetic and those unshared cells can often be determined with certainty.

Strategy 4: Mark Blanks as Aggressively as Shading

Most beginners focus on finding cells to shade. Expert solvers mark blank cells just as aggressively. Every confirmed blank is information — it constrains all the clues that include that cell in their neighbourhood, which can unlock deductions elsewhere on the board.

When a clue's count is already fully satisfied by confirmed shaded cells, every remaining unresolved cell in its neighbourhood must be blank. Mark them all immediately. This cascade of blank-marking is how a solved section ripples outward to unlock the next section.

• When a clue's shaded count is met, blank all remaining neighbours.
• When a clue's blank count is met, shade all remaining neighbours.
• Each blank or shade you place can unlock multiple adjacent clues at once.
• Always re-scan neighbouring clues after placing any new mark.

Strategy 5: Work the Ripple Effect

Mosaic puzzles are designed so that one deduction leads to another. Once you place a mark — shaded or blank — always immediately check every clue whose neighbourhood includes that cell. A newly confirmed blank in one area often satisfies a nearby clue's count, which in turn forces a cascade of marks in the next region.

This ripple effect is why experienced solvers rarely get stuck. Instead of scanning the whole board looking for the next move, they follow the chain of consequences from the last mark they placed. A single correct deduction can resolve five or six cells in a row.