Masyu
Thread one closed loop through every pearl.
How to play Masyu
Draw one single closed loop that passes straight through the centre of cells and visits every pearl. On a white pearl the loop must go straight through, but it has to turn in at least one of the two neighbouring cells. On a black pearl the loop must turn, and it must go straight in the cell immediately before and after. Click or drag between two dots to add or remove a segment; you win when the loop is one closed line that satisfies every pearl.
The two pearl rules
Masyu is one closed loop threaded through a grid, and everything hinges on two rules for the pearls. A white pearl means the loop runs straight through that cell, but it has to turn in at least one of the cells immediately before or after. A black pearl is the opposite: the loop turns on the pearl itself, then travels straight for one full cell on both sides of the turn. Get those two shapes into your hands and most of the puzzle solves itself. Draw a segment by clicking or dragging between two dots, and do it again to remove one.
How to actually solve one
Start with the black pearls near an edge or corner. A black pearl needs a straight cell on each side of its turn, so one sitting against a wall can only bend one way. That forces segments you can ink in right away. White pearls in a row are the other big lever: two or three of them in a line create a contradiction if you try to run straight through all of them, because the required turns collide, so the loop is forced to approach that run a particular way. Work outward from those forced starts, always asking what a placed segment demands next. The loop can never branch or cross itself, so any move that makes a dead end, or a small closed circle that doesn't cover every pearl, is wrong. You've won when there's exactly one continuous loop and every white and black pearl obeys its rule.
Forced shapes worth memorizing
- A black pearl in a corner region is nearly solved before you touch it. Neither arm can poke through a wall, so both of its two-cell arms must point into the board, and the whole L is often decided on the spot.
- A black pearl on an edge always sends one full arm straight into the board. Only its along-the-wall arm has any freedom left to argue about.
- Two black pearls side by side push apart. An arm cannot run through the neighbouring pearl, because every black pearl is a turn and an arm needs straight cells, so each pearl's arm on that shared line points away from the other.
- Three white pearls in a row can't all be passed straight along their shared line. If the loop ran along the line through the middle one, both of its line neighbours would be white pearls passed straight, leaving the middle pearl with no adjacent turn. So the middle one, at least, gets crossed the other way.
- A white pearl on the border is always passed along the border, since crossing it the other way would need a cell outside the grid.
Use the loop against itself
The single-loop rule isn't just a win condition; it's a solving tool. Any move that seals a small closed circle before every pearl is collected is illegal, so when two loose ends creep toward each other, check what joining them would do. If the join would close a loop that leaves pearls outside, you've proven the join wrong, and the ends must route away from each other instead. Near the end of a puzzle this test often decides the last several segments on its own. Dead ends work the same way. The loop never branches, so a segment that would leave a stub with nowhere to go is wrong the moment you imagine it. Solvers who constantly check those two things, closure and stubs, hardly ever need to erase.
A pearl by mistake
Masyu comes from Nikoli, the Japanese publisher behind the modern spread of Sudoku. It first appeared in the company's magazine in 2000 with white pearls only; the black pearls arrived the following year and completed the design. The name is an accident. Nikoli's late president Maki Kaji glanced at the puzzle's original title, which used the kanji for pearl, misread it as masyu, and the misreading stuck as the official name. The result is a puzzle with one of the smallest rule sets anywhere, a loop and two pearl behaviours, that still produces sharp deductions with no numbers to lean on, just the geometry of a single line. That's what gives it a clean, almost meditative feel once you trust the two rules.
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Masyu: frequently asked questions
What is the difference between white and black pearls?
The loop passes straight through a white pearl (and must bend just before or after it), while it must make a right-angle turn on a black pearl (and run straight in the cells on either side).
Does the loop have to fill the whole grid?
No. The loop only has to be a single closed line that passes through every pearl and never crosses or branches. Empty cells the loop skips are fine.
What does a white pearl require?
The loop goes straight through the white pearl, and it must also turn in at least one of the two cells directly next to it. Straight through the pearl, a bend on at least one side.
What does a black pearl require?
The loop turns on the black pearl itself, and then runs straight for one full cell on each side of that turn before it's free to bend again.
Where should I start solving?
Black pearls near edges and corners. A wall usually leaves them only one legal bend, which forces segments you can commit to immediately and build outward from.
How do I draw and undo segments?
Click or drag between two adjacent dots to add a segment, and repeat the action on the same segment to remove it if you change your mind.
How does the single-loop rule help me solve faster?
Treat it as a test. If joining two loose ends would close a small loop that leaves pearls uncollected, that join is forbidden, so the ends must route elsewhere. Late in a puzzle this one check often places the last few segments by itself.
When is the puzzle finished?
When a single closed loop covers the board with no branches or crossings, and every pearl satisfies its own straight-or-turn rule. A stray small loop that misses pearls doesn't count.
Is Masyu free to play?
Yes. Masyu is completely free on Inkplay, with no download, no sign-up, and no in-game purchases. Open the page and play instantly on desktop or mobile.
Can I play Masyu unblocked?
Yes. Masyu runs entirely in your browser with no download, install, or plugins, so it loads instantly and keeps working even on school or work networks where bigger game sites get blocked.
More games to play
In the mood for more? Try 2048, Memory Match, Lights Out, Minesweeper, or browse all puzzle games and the full games list on Inkplay. Masyu also appears in Logic Puzzles.