ThePuzzleLabs

Slitherlink

Hard — 10×10

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Play Hard Slitherlink — ThePuzzleLabs

Try this Hard Slitherlink puzzle on ThePuzzleLabs.

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Classic
003333001130113000133331011131331001133100003

How to Play Slitherlink

Rules

  • Draw a single closed loop along grid edges.
  • Each numbered cell tells you how many of its 4 edges are part of the loop.
  • The loop has no branches and no dead ends — every point on the loop connects exactly 2 edges.
  • Blank cells give no information.

Controls

  • Click/tap an edge to cycle: empty → line → × → empty
  • Right-click to mark × (excluded) directly
  • U or Ctrl+Z Undo
  • Ctrl+Y Redo
  • H Hint

Clue Colours

  • Default — no edges set yet
  • Orange — some edges set, not enough
  • Green — exactly satisfied
  • Red — too many edges

Solve This Puzzle?

This will fill in the complete solution. The puzzle will be marked as “solved with reveal” rather than self-solved.

About hard slitherlink

Hard slitherlink runs on a 10×10 grid with 45% clue density. More cells are blank, which means fewer starting points and longer deduction chains.

Loop closure reasoning is where hard puzzles separate from medium. You need to track which vertices are connected by the partial loop and prevent premature sub-loops. If drawing a line between two vertices that are already connected would close a loop that doesn't include all existing lines, that edge is excluded.

Use the excluded-edge markers (× marks) aggressively. Knowing what isn't part of the loop narrows possibilities just as much as knowing what is. On 10×10, you often solve more edges through exclusion than through direct line placement.