This page explains how to complete Slitherlink interactive puzzles.

Slitherlink puzzles can be played interactively on the computer, offering many features and advantages compared to pencil and paper. This section explains everything about how to play Slitherlink Interactive.

Drawing and excluding links

Drawing and excluding links

Slitherlink Interactive is played by linking pairs of dots around clues. First click links dots with a line, second click marks X to indicate link is excluded and the third click brings path back to its original state.

Completing clues

Completing Clues

When all paths around a clue are accounted for, the clue will change color to indicate it is completed.

Highlighting loop segments


Highlighting a loop segment is helpful when checking whether two loops are about to occur. To highlight a loop segment, click mouse on any of the clues belonging to the segment.



All game functions are accessed through the toolbar. For some toolbar buttons, keyboard shortcut keys are also available as listed below.

Zoom in

Zoom In

Enlarge small puzzles for best viewing on your screen.

Zoom out

Zoom Out

Reduce large puzzles for best fit on your screen.

Undo (Keyboard: U)


Go back as many steps in the game as you want.

Redo (Keyboard: R)


Go forward after using Undo as many steps as you want.

Restart puzzle


Restart puzzle to solve from the beginning.

Check puzzle (Keyboard: C)

Check Puzzle

Check all links and X markings for errors.





Show elapsed solving time.

Show solution

Show solution

Show solution of the puzzle. Using this button will also end the game.



Open Preferences dialog box. New preferences will be automatically saved on the computer.

Preferences dialog box

  • Show errors: Check this box to automatically show link errors during the game. Link errors are shown if the number of links around a clue is correct and one or more links are wrong, or if all paths around a clue are accounted for and there is one or more error.
  • Auto complete: Check this box to automatically mark with X remaining paths around a clue when the number of links is correct.
  • Auto exclude: Check this box to automatically exclude blocked paths.



Open About dialog box to see puzzle size, difficulty, ID, title and other information.



Open Slitherlink Interactive page you are reading now.

Print options

Print options 

Open Print dialog box. New print options will be automatically saved on the computer.

Print dialog box


  • Puzzle: Select to print puzzle.
  • Solution: Select to print solution.
  • Current state: Select to print current solution state. 


  • Preferred image scale: Reduce or enlarge printout.
  • Attempt to reduce to page: Check this box to fit large puzzles on a single page. When this box is unchecked, large puzzles will print in multiple pages according to selected scaling.
  • Attempt to enlarge to page: Check this box to fit small puzzles on a whole page. When this box is unchecked, small puzzles will print according to selected scaling.
  • Select optimal orientation: Check this box to automatically select puzzle orientation.

Save puzzle (Keyboard: S)

Save puzzle

Save current state of the puzzle.

Logic Puzzles are provided courtesy of