Slitherlink: Loop the Snake 4+

Looping fence puzzles

Conceptis Ltd.

    • 4.8 • 332 Ratings
    • Free
    • Offers In-App Purchases



Surround each clue with lines to form one single loop! Each puzzle consists of a rectangular lattice of dots with some clues in various places. The object is to connect the dots surrounding each clue so that the number of lines equals the value of the clue and the lines around all clues form one continuous loop with no crossings or branches. Empty squares may be surrounded by any number of lines.

Slitherlink are addictive loop-forming puzzles which were invented in Japan. Using pure logic and requiring no math to solve, these fascinating puzzles offer endless fun and intellectual entertainment to puzzle fans of all skills and ages.

The game features 2-finger tapping for quick zoom, auto complete clues setting and a link segment highlighting option to help to avoid creating separate loops. To help see the puzzle progress, graphic previews in the puzzle list show the progress of all puzzles in a volume as they are being solved. A Gallery view option provides these previews in a larger format.

For more fun, Slitherlink contains no ads and includes a Weekly Bonus section providing an extra free puzzle each week.


• 200 free Slitherlink puzzles
• Extra bonus puzzle published free each week
• Multiple difficulty levels from very easy to extremely hard
• Grid sizes up to 16x22
• Puzzle library continuously updates with new content
• Manually selected, top quality puzzles
• Unique solution for each puzzle
• Hours of intellectual challenge and fun
• Sharpens logic and improves cognitive skills


• No ads
• Unlimited check puzzle
• Unlimited Undo and Redo
• Auto complete clues
• Highlight link segment
• Quick zoom using 2-finger tap
• Concurrently playing and saving multiple puzzles
• Puzzle filtering, sorting and archiving options
• Dark Mode support
• Graphic previews showing puzzles progress as they are being solved
• Portrait and landscape screen support (iPad only)
• Track puzzle solving times
• Backup & restore puzzle progress to iCloud


Slitherlink have also become popular under other names such as Fences, Loop the Loop, Loopy, Suriza, Dotty Dilemma and Number Line. Similar to Sudoku, Kakuro and Hashi, the puzzles are solved using logic alone. All puzzles in this app are produced by Conceptis Ltd. - the leading supplier of logic puzzles to printed and electronic gaming media all over the world. On average, more than 20 million Conceptis puzzles are solved each day in newspapers, magazines, books and online as well as on smartphones and tablets across the world.

What’s New

Version 4.8

This version improves performance and stability.

Ratings and Reviews

4.8 out of 5
332 Ratings

332 Ratings

Russkle ,

Challenging and fun

I play several Conceptis games that I love, but this may be my favorite. It took me a bit to catch on to how you play, but it was never one of those that was just too frustrating and made me want to give up. I love the design and playability of the game—I’ve tried a couple other apps with this game, and they were definitely more clunky.

I have anxiety disorder, and I find when I’m feeling especially anxious, this game is strangely calming—I think maybe it’s partially having something that has a predictable result.

Monbebebebebebebebe ,

Once you understand

Once you understand the basic rules of where lines cannot be placed it makes it feel less daunting to complete the puzzles. I play these when I want to relax or detox from social media lately & it’s been really awesome to find a puzzle game that is the right amount of challenging but not overwhelmingly hard that I get frustrated.

I do wish there was an option/tool to choose between adding lines and placing the X markers instead of double tapping to get to the X. Since I start the puzzles marking out where not to place a line it would be easier to be able to switch from one to the other with the click of one button instead of repeatedly double tapping, I hope that makes sense. But other than that I love this app.

MichelleC333 ,

Great fun, offers SO many different puzzles

This app is great fun, thought-provoking and offers SO much variety of different puzzles at various difficulty and sizes. You’ll need to read the Help Menu to learn how to play. You’ll want to read (I highly recommend reading) the Techniques section as well, it’s a lifesaver. I even wrote them down to use as a reference until I knew them by heart. I am a Conceptis Puzzles fan and this is one of my favorites.

App Privacy

The developer, Conceptis Ltd., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • Identifiers
  • Usage Data

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Some in‑app purchases, including subscriptions, may be shareable with your family group when Family Sharing is enabled.

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Sudoku: Classic & Variations

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