Minesweeper Solver —
every cell that's actually certain.

Field guide

How the Minesweeper Solver works.

In Minesweeper, each revealed number tells you how many mines sit among its immediately surrounding cells. This tool reads your current board and works out which unrevealed cells are guaranteed safe or guaranteed mines — the same deductions an expert player makes by hand, just applied to the whole board at once.

Using the solver

Enter every revealed number exactly as shown, mark any cells you've already flagged, and enter the total mine count from the game's counter. The solver highlights every cell it can prove safe or prove mined; if it can't, it tells you plainly rather than guessing.

The algorithm: constraint satisfaction over overlapping numbers

Every revealed number becomes a simple equation: “N mines are distributed among these specific unrevealed neighbor cells.” With many numbers bordering the same unrevealed region, their equations overlap, and two classic deductions fall out of comparing them:

• Subset elimination. If one number's neighbor-set is entirely contained within a second number's neighbor-set, subtracting one equation from the other isolates the cells unique to the larger set — often immediately proving some of them safe or mined.
• Global mine-count check. The total mines remaining across the whole board (counter minus flags placed) is itself a constraint. Comparing it against every local region can prove cells safe that local number comparisons alone can't resolve.

The solver repeats these comparisons across every pair of overlapping constraints until no further cell can be proven either way — at which point any remaining unrevealed cells genuinely require a guess (or more information), and the tool says so instead of fabricating an answer.

Worked example

Say a “1” and a “2” are adjacent, and the “1”'s single unrevealed neighbor is also one of the “2”'s three unrevealed neighbors. Subtracting the “1”'s equation from the “2”'s isolates the “2”'s other two neighbors as together containing exactly one mine fewer than before — sometimes enough, combined with a third nearby number, to pin an exact cell.

Tips for solving it yourself

• Look for a “1” with only one unrevealed neighbor. That neighbor is a guaranteed mine — flag it immediately.
• Compare overlapping numbers, not just isolated ones. The subset trick above is the single most useful manual technique once the easy deductions run out.
• Track the mine counter. Late in a board, the remaining mine count relative to remaining unrevealed cells can force moves no single number reveals on its own.