Masyu

1 player · 5-25 min per session

Draw a single non-intersecting loop that passes through every circled cell while satisfying each circle’s constraint.

Players: 1P Session length: 5-25 min

Puzzle

Goal & Core Rules

Draw a single non-intersecting loop that passes through every circled cell while satisfying each circle’s constraint.

The loop is a single closed line with no branches and no crossings.
White circles must be passed straight through, but the loop must turn in the previous and/or next cell.
Black circles must be turned on, and the loop must go straight through the adjacent cells before and after the turn.
Every circle must be included in the loop.

Classic

Standard Masyu rules with white and black circles.

Controls

Mouse

Left click or drag: apply the current input mode continuously.
Right click or drag: apply the opposite mode quickly.
Click the same edge again to clear the current mark.

Keyboard

The current web build does not provide dedicated keyboard shortcuts.

Touch

Choose [Line Mode] or [Block Mode] from the bottom or side panel, then tap an edge.
Tap the same edge again to clear it.
Use pinch zoom and scroll together on larger boards.

Beginner Tips

Start from the edges: circle rules often force the loop to avoid or hug borders in predictable ways.
Treat black circles as “turn anchors”—they usually create long straight segments extending out.
Whenever you place a line segment, immediately mark what becomes impossible around it to avoid contradictions.

Advanced Tips

Use loop logic: prevent creating small closed loops or dead ends before all circles are satisfied.
Chain constraints: a forced straight through a white circle often propagates turns several steps away.
Look for “must-join” points where two partial paths cannot remain separate without breaking circle rules.

Origins & History

Masyu is a loop-drawing logic puzzle designed and published by Nikoli. Wikipedia notes that an early form appeared in Nikoli’s Puzzle Communication magazine under a “pearl necklace” title, later adding black circles and adopting the shorter name “Masyu.”

Sources

Masyu — Wikipedia (History)

FAQ

Can the loop cross itself?

No. The loop must be a single non-intersecting closed curve.

Do I have to include every pearl?

Yes—every circle is a required constraint point on the loop.

What’s the biggest beginner mistake?

Creating a small closed loop too early, which prevents satisfying remaining pearls.