Minesweeper is a game of pure deduction: a grid of covered squares hides a fixed number of mines, and every number you uncover tells you exactly how many mines touch that square. Clear every safe square without clicking a mine and you win — no luck required on most boards, and no reflexes required on any of them. This version runs free in your browser with no download and no signup, and it keeps your best time saved locally on your device.
What the Numbers Mean — and the Two Rules That Solve Every Board
Every number counts the mines in the eight squares touching it, diagonals included. That neighbour count changes at the edges, and this matters more than beginners expect: a corner square touches only 3 others, an edge square touches 5, and an interior square touches 8. So a 3 in the corner means all three of its neighbours are mines — a certainty you would never get from a 3 in the middle of the board. A blank square means zero mines nearby, which is why blanks open up in a cascade: the game auto-clears every neighbour of a zero, and repeats outward until it hits numbers.
Two rules do almost all the work. Rule one, the mine rule: if a number equals the count of still-covered squares around it, every one of those squares is a mine. A 1 with exactly one covered neighbour left — that neighbour is a mine, no guessing involved. Rule two, the clear rule: if the mines you have already identified around a number equal that number, every remaining covered neighbour is safe. A 2 with two flags beside it is finished; anything else touching it can be opened immediately.
The third rule is the one that separates people who get stuck from people who don't: subtraction between overlapping clues. If clue A's covered squares are all also neighbours of clue B, then B's remaining squares — the ones A doesn't touch — contain exactly (B minus A) mines. A 1 and a 3 sharing two covered squares means the 3's other squares hold exactly 2 mines. Every named pattern below is just this subtraction applied to a shape you have seen before, which is why memorising the shapes is faster than re-deriving them under a clock.
Is the First Click Always Safe? Where to Click First
On a fresh board you have zero information, so the opening click is a coin flip in principle — which is why nearly every modern implementation, this one included, refuses to end your game on move one. The standard behaviour is that the mine layout is generated or adjusted after you click, so your first square is never a mine. Some versions go further and guarantee your first click lands on a zero, opening a whole region rather than a lone number. Either way, the timer starts on that first click, not when the page loads, so there is no cost to thinking before you press.
Where you click still changes your game, because it changes how much board you get for free. The odds that a square is a blank depend on how many neighbours it has to keep clean. On Expert, at roughly 20% mine density, a corner has only 3 neighbours and is blank about half the time; an edge square has 5 neighbours and is blank about a third of the time; an interior square has 8 and is blank only about one time in six. Corners are the most likely to open something. But when an interior square does come up blank, the cascade is far larger, because it can expand in every direction instead of being clipped by the wall.
The practical opening most strong players use is a compromise: click a corner or a square one or two in from an edge, and if you get a single number instead of an opening, click another corner rather than nibbling at the number you just revealed. Multiple separate openings are worth more than one, because deduction lives on the boundary between opened and covered squares — two openings mean two frontiers, and the clues on them often overlap enough to crack the region between them without a guess.
The Patterns Worth Memorising: 1-2-1, 1-2-2-1 and 1-1-X
The 1-2-1 is the one to learn first. Three numbers reading 1, 2, 1 in a straight line, with three covered squares in a row alongside them: the mines are under the two 1s, and the square under the 2 is safe. The proof takes a second — if the middle covered square were a mine, both 1s would be satisfied by it, which would leave the 2 seeing only that single mine. Contradiction, so the middle is clear and the outer two must be mines. The pattern works in every orientation: horizontal, vertical, read left to right or right to left.
The 1-2-2-1 is its bigger sibling and resolves the other way round. Four numbers reading 1, 2, 2, 1 with four covered squares alongside: the mines sit under the two 2s, and the squares under the 1s are safe. Beginners often flag by reflex under the 1s because 1-2-1 trained them to — check the digits before you commit. Between them these two patterns break open most walls and most straight boundaries you will meet on Intermediate and Expert.
The 1-1-X is subtler and needs a condition: a wall, or already-opened squares, closing off one side. Take two 1s side by side where the first 1 has only two covered neighbours, and the second 1 touches those same two plus one more further along. The first 1 tells you a mine lives in the shared pair. That mine already satisfies the second 1, so the extra square — the X — is safe, every time. It is the pattern that lets you walk along a wall opening square after square, and the single most common reason a boundary that looks like a guess actually isn't. If the first 1 has a third covered neighbour the logic collapses, so check the count before you trust it.
When You're Stuck: the 50/50 and How to Guess Less
Minesweeper boards are not all fully solvable. A genuine 50/50 happens when two covered squares are symmetric with respect to every clue that touches them — most often a pair trapped against a wall, or the classic two-square corner where one holds a mine and nothing on the board can tell you which. When you truly have one of these, there is no technique that beats a coin flip. But most positions that feel like a 50/50 are not one, and there are three checks to run before you flip.
First, use the mine counter as a global clue. The number of mines left plus the number of covered squares left is a constraint that overrides local reasoning. If 3 mines remain among 40 covered squares, an untouched square far from any boundary is a mine only about 7% of the time — vastly better than the 50% you were about to accept. Conversely, if 12 mines remain among 14 covered squares, the safe move is the one adjacent to your solved region, not the open field. Second, compare probabilities rather than taking the first guess offered: a 1 touching three covered squares makes each of them a 33% mine, so guess there instead of at a true 50/50. Third, look for a clue two steps back from the boundary — a distant number combined with the mine total often breaks a symmetry that the local squares cannot.
When you do have to flip, flip early and flip where the payoff is biggest. Guessing at the start of a stuck position costs you less than grinding the rest of the board first and losing on the same square at the end. And prefer a guess that, if correct, opens new territory — a square in a wide covered region rather than a lone square wedged against a wall, because the wedged square usually reveals a number you already could have predicted. Saving the forced guess for last is the single most common way players lose otherwise-won Expert boards.
Flags: When to Use Them, When to Skip Them, and How to Flag on Mobile
A flag is a marker you place on a square you have proven is a mine. It changes nothing about the board — the mine is there whether you mark it or not — so a flag is purely a note to yourself, and every flag costs you a click. That is why many fast players use no-flag play: they identify mines mentally, open only the squares they have proven safe, and never spend the input. Under the standard rules you win by uncovering every safe square, not by flagging every mine, so a no-flag win is a full win and the board ends the moment the last safe square opens.
The case for flagging is memory and chording. Flags make the clear rule visible at a glance — a 3 with three flags around it is visibly finished, and you can open its remaining neighbours without recounting. On boards that support chording, clicking a fully flagged number opens all its remaining neighbours in one action, which turns those flags into a speed gain rather than a cost. The productive middle ground: flag inside dense clusters and along complicated boundaries where you will need to recount, and skip flags in sparse regions where the deduction is obvious and one-step.
Controls differ by device. On a desktop mouse, right-click plants and removes a flag. On a laptop trackpad, use a two-finger tap, or hold Ctrl and click on a Mac. On a phone or tablet, press and hold a square for about half a second instead of tapping — a tap opens, a hold flags. If holding feels slow when you are placing several flags in a row, look for a flag-mode toggle: switching it on makes a plain tap place flags instead of opening squares, which is much faster on touch, as long as you remember to switch it back before your next dig.
Beginner vs Intermediate vs Expert: Grid Sizes, Mine Counts and Density
The three standard difficulties come from the original Windows versions and are still the benchmark everywhere. Beginner is a 9×9 grid — 8×8 in some older builds — with 10 mines, so 81 squares at about 12% density. Intermediate is 16×16 with 40 mines: 256 squares at about 16%. Expert is 16 rows by 30 columns with 99 mines: 480 squares at about 21%. The grid grows roughly six-fold from Beginner to Expert, but the number that actually decides how the game feels is the density, which rises by two thirds.
That density shift changes the deduction, not just the workload. At 12% you get large blank cascades and long stretches of 1s, so the clear rule alone carries you a long way. At 21% you get far fewer zeros, boundaries made of 2s and 3s instead of 1s, and clue sets that overlap constantly — which is exactly where subtraction and the 1-2-1 and 1-2-2-1 patterns start earning their keep. Expert also produces more genuine 50/50s, simply because more of the board is a narrow boundary rather than an open field.
A sensible progression: stay on Beginner until you can finish without a single guess, which proves you are applying the two rules rather than clicking hopefully. Move to Intermediate for pattern practice — it is dense enough to produce 1-2-1s regularly but small enough that a loss costs a minute, not five. Treat Expert as the real test, and expect to lose boards you played correctly. Rough targets to aim at once the deduction is solid: under 15 seconds on Beginner, under a minute on Intermediate, under three minutes on Expert. Your best time on each is saved in this browser, so you can see the curve without an account.
Questions people ask
Is the first click in Minesweeper always safe?
Yes. The mine layout is settled after your first click, so the opening move can never end the game. Where you click still matters for what it reveals: corners have only 3 neighbours and come up blank most often, while interior squares are blank less often but produce much bigger cascades when they do.
Do you have to guess in Minesweeper?
Sometimes, but far less often than it feels. A true 50/50 only exists when two covered squares are identical with respect to every clue touching them — usually a pair trapped against a wall. Before guessing, check the mine counter against the number of covered squares left; a square in an open region is often a 5-10% risk when the boundary square in front of you is a 50% risk.
Do I need to flag every mine to win?
No. Under the standard rules you win by uncovering every safe square, and the board ends the moment the last one opens — flags are notes for you, not a win condition. Many fast players use no flags at all. The useful compromise is flagging in dense clusters where you will need to recount, and skipping them in obvious one-step regions.
What does the 1-2-1 pattern mean?
Three numbers reading 1, 2, 1 in a line, with three covered squares alongside: the mines are under the two 1s and the square under the 2 is safe. Its sibling, 1-2-2-1, resolves the opposite way — the mines are under the two 2s and the squares under the 1s are safe. Both work in any orientation, so check the digits rather than the shape before you commit.
Is this Minesweeper free, and do I need an account?
It is free, runs entirely in your browser, and needs no download and no signup. There are no accounts, so your best time is stored locally on the device you played on — clearing your browser data or switching devices will reset it.
How to play Minesweeper
- Numbers show how many mines touch that cell.
- Toggle flag mode (or long-press) to mark suspected mines.
- Open every safe cell to win — tap a mine and it’s over!
Minesweeper is free to play online at Trivio — no download, no signup, works on desktop and mobile. Your best score is saved in your browser.