Minesweeper
Tap a square to open it. A number tells you how many of the eight squares around it hold mines. Flag by long-pressing or right-clicking, or switch on flag mode on a phone. The first square is always safe — mines are placed after your first tap, and that square and its eight neighbours are left empty. Records stay in this browser.
Tap a square to open it. A number counts the mines in the eight squares around it. Flag by long-pressing or right-clicking. Tapping a number opens the rest once its flags match.
Beginner: 10 mines in 81 squares. Intermediate: 40 in 256
Mine density rises from 12.3% to 15.6% and the board is more than three times larger. The clock starts at the first square you open, not when the board is made, and counts in seconds. A record is set only by a won game, only when shorter than that level's record, and stays in this browser. When you blow up, every mine is revealed and only the one you stepped on is painted red.
Two cases where one number settles it
If a number minus the flags around it equals the number of unopened neighbours, those neighbours are all mines. If the flags already match the number, the remaining neighbours are all safe, and tapping the number opens them at once. When neither applies, overlap two adjacent numbers — a 1-2-1 along a wall means mines in front of both 1s and a safe square in front of the 2.
Flags are only a bookkeeping mark
The mines-left figure is the mine total minus the flags placed; whether the flags are right is never checked. Place more flags than mines and it goes negative. A flagged square will not open when tapped, so a wrong flag has to be removed first. The win condition is opening every non-mine square, so you can finish without placing a single flag. In flag mode tapping an open number still opens its neighbours rather than flagging.
Common questions
QCan the very first tap blow up?
No. Mines are placed after your first tap. That square and its eight neighbours are left empty, so the first square is always a zero and opens a cascade. Across 10,000 boards on both levels, the first tap never hit a mine and never landed on a number. It opens 37.7 squares on average at beginner level, 49.0 at intermediate.
QDo some boards force a guess?
Yes — a long-standing property of the game. Pushing 3,000 boards as far as two human rules go — reading one number against its own neighbours, and overlapping two numbers (the trick that cracks 1-2-1) — left 19.2% of beginner boards and 46.0% of intermediate ones with no certain move. At that point you guess.
QTapping a number opened several squares.
Tapping an open number opens its remaining neighbours once the flags around it match that number. It saves opening them one by one. If a flag is wrong it blows up — opening only when it is safe would hand you the answer for free.
QWhy is there no expert board?
The classic expert board is 30 squares wide, which is unusable on a phone: on a 390px screen each square would be 11px, far smaller than a fingertip. Beginner 9×9 with 10 mines and intermediate 16×16 with 40 give quite different games on their own.
QDo I have to flag every mine to finish?
No. The game ends the moment every non-mine square is open. If the only squares left are mines, you have won without flagging them. Flags are just a way of keeping count of which unopened squares are mines.
QThe mines-left counter went negative.
You have placed more flags than there are mines. The screen does not check whether flags are right; it only subtracts their count. Some flag is wrong, so find a number with more flags around it than its value and remove one.