Slitherlink

About Slitherlink

Slitherlink is a classic loop puzzle, also called Loop the Loop or Fences, free to play online. Connect the dots on the grid to draw one continuous loop that never crosses or branches. Each number tells you how many of the four sides around that cell belong to the loop, and empty cells can have any count. Tap an edge to draw a line, switch to cross mode to rule edges out, and watch the loop take shape as the logic falls into place. Begin with a 7x7 easy square grid, then try normal and hard puzzles, bigger boards, or unusual tilings such as hexagons, triangles, Cairo pentagons and Penrose tiles. Every puzzle has a single solution, and your game is saved on this device so you can finish it later.

Game by Simon Tatham, used under the MIT license.

How to play

Tap an edge to draw a loop segment; tap again to remove it. Switch to Cross mode (or long-press) to mark an edge as empty. Mouse: left-click draws, right-click crosses. Ctrl+Z to undo, N for a new puzzle.