How do I place a flag on a phone?

Press the button to switch from "opening cells" to "placing flags", then tap. Press it again to switch back. A toggle rather than a long press, because long-press thresholds vary by device and produce accidental openings.

Why is the first click always blank?

Mines avoid the clicked square and its eight neighbours, so that square has zero mines around it. Squares with zero neighbouring mines open in a chain, so the first click always reveals a wide area.

When does the clock start?

When you open the first square. Choosing a size or looking at the board costs nothing, and the clock stops the moment you win.

Can anyone see my times?

No. They live only in this browser on this device, and there is no leaderboard or account. Private browsing may block storage entirely.

Does it work offline?

Yes. Once the page has loaded, everything runs inside the browser.

The pattern you use most

If a "2" has exactly two unopened neighbours left, both are mines. Conversely, if a "2" already has two flags around it, every remaining unopened neighbour is safe. Those two patterns alone carry most of a board. Harder positions begin where you have to combine that reasoning across two different numbers.

Read two numbers together

Take an adjacent "1" and "2" that share two unopened squares, where the "2" also sees one square the "1" cannot. The "1" tells you exactly one of the shared pair is a mine — which forces the "2"'s extra square to be a mine too. Positions that look stuck under a single number often resolve immediately when you bring the neighbour into it.

Some positions genuinely cannot be deduced

Fifty-fifty guesses are structurally part of this game, especially at the edges of the board and where mines cluster. The convention is to guess the square that reveals the most if you are right, and costs the least if you are wrong. The luck cannot be engineered away.

Times are kept per size

Fastest times are stored separately for 9x9, 12x14 and 14x18. Different sizes have different difficulty and duration, so there is nothing meaningful in comparing them. Switching size shows that size's record.

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Minesweeper

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Each number tells you how many mines sit in the eight squares around it. That is the only clue you get. Clear every square that is not a mine — and the first click can never lose.

Mines left

Seconds

Fastest

—

Tap to open. Right-click, or switch to "placing flags", to mark a mine

No time recorded for this size yet

A number counts the mines in the eight squares around it. When the count equals the unopened squares, those squares are all mines.

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Why this one

The first click cannot lose: Mines are not placed when the board is built. They are laid out after your first click, avoiding that square and the eight around it. Placing them up front means a certain share of games end on move one, which is luck rather than deduction. It also guarantees the first click opens into a blank area, so you always start with something to read.
Flags do not decide the win: A flag only stops a square from being opened; whether it is correct is never checked. Winning means every non-mine square is open. Deciding the win by flag count would let you win by guessing where to plant them.
Close it and come back: The board, the size and the elapsed time are stored on this device. Fastest times are kept separately per size, so a 9x9 record never mixes with a 14x18 one.

How to play

Click anywhere
The first click is always safe. A blank area opens up from it and the numbers appear.
Narrow down the mines
Each number counts the mines in the eight squares around it. When the number equals the unopened neighbours, all of them are mines.
Open everything else
Clearing every non-mine square wins. Right-click, or switch the button to "placing flags", to mark one.

Good to know

The pattern you use most: If a "2" has exactly two unopened neighbours left, both are mines. Conversely, if a "2" already has two flags around it, every remaining unopened neighbour is safe. Those two patterns alone carry most of a board. Harder positions begin where you have to combine that reasoning across two different numbers.
Read two numbers together: Take an adjacent "1" and "2" that share two unopened squares, where the "2" also sees one square the "1" cannot. The "1" tells you exactly one of the shared pair is a mine — which forces the "2"'s extra square to be a mine too. Positions that look stuck under a single number often resolve immediately when you bring the neighbour into it.
Some positions genuinely cannot be deduced: Fifty-fifty guesses are structurally part of this game, especially at the edges of the board and where mines cluster. The convention is to guess the square that reveals the most if you are right, and costs the least if you are wrong. The luck cannot be engineered away.
Times are kept per size: Fastest times are stored separately for 9x9, 12x14 and 14x18. Different sizes have different difficulty and duration, so there is nothing meaningful in comparing them. Switching size shows that size's record.

FAQ

How do I place a flag on a phone?: Press the button to switch from "opening cells" to "placing flags", then tap. Press it again to switch back. A toggle rather than a long press, because long-press thresholds vary by device and produce accidental openings.
Why is the first click always blank?: Mines avoid the clicked square and its eight neighbours, so that square has zero mines around it. Squares with zero neighbouring mines open in a chain, so the first click always reveals a wide area.
When does the clock start?: When you open the first square. Choosing a size or looking at the board costs nothing, and the clock stops the moment you win.
Can anyone see my times?: No. They live only in this browser on this device, and there is no leaderboard or account. Private browsing may block storage entirely.
Does it work offline?: Yes. Once the page has loaded, everything runs inside the browser.

Related tools

Why this one

How to play

Click anywhere

Narrow down the mines

Open everything else

Good to know

FAQ