Guides
How this Minesweeper works
A short and checkable description of what the game does.
The game runs entirely in your browser. Mines are placed at random when you open your first cell, outside that cell and its neighbors. The daily board uses the UTC date as its seed. Your best times and settings are saved in your browser's local storage, and nothing is sent to a server.
The game
- The board is a grid of covered cells. The mines are not placed until your first click.
- When placing mines, the clicked cell and its neighbors are excluded, so the first click opens an empty area.
- If a custom board is so dense that there is no room for the whole safe zone, only the clicked cell is kept clear.
- Opening an empty cell opens its neighbors using a loop, not recursion, so even the largest board cannot overflow the stack.
- The timer starts at your first click and is counted in wall time.
Random and daily boards
Normal boards use a short random seed from your browser's secure random source. The Mulberry32 generator turns the seed into a shuffle of the allowed cells, and the first mines in the shuffle are used. The daily board uses the UTC day number as the seed, so every browser creates the same board, and a safe opening is applied for you.
What is stored
- Your best time for each of the three levels, and for today's daily board.
- Your last difficulty and custom board settings.
- Nothing else. There are no accounts and no leaderboards, and nothing leaves your device.
Frequently asked questions
Can I check this?
Yes. Open your browser's developer tools, look at the Network tab while you play, and see that no requests are made.