Slitherlink Puzzle: Play Slitherlink Free Online

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In this guide

• How to play Slitherlink
• The beginner pattern cheat sheet
• Sizes and difficulty tiers
• The Daily Loop
• Stars, Check and hints
• 7 tips to solve Slitherlink faster
• Slitherlink FAQ
• Final verdict

How to play Slitherlink

The board is a grid of cells, and some of the cells hold a number: 0, 1, 2 or 3. You draw along the edges between the cells, never through them. The one big rule is the loop rule: when you finish, all of your lines join up into one single closed loop. The loop can wind and turn as much as it likes, but it can never branch like a tree, never cross itself, and never split into two smaller loops. One loop, and only one.

The second rule lives in the numbers. A numbered cell is a promise: exactly that many of its four sides must be part of the loop. A cell marked 3 needs three of its sides drawn. A cell marked 0 needs none of them, so all four of its sides can be ruled out the moment you see it. A cell with no number makes no promise at all: the loop may pass along none of its sides, some of them, or all of the way around it. The whole puzzle is the art of making every promise true at the same time with a single loop.

There is a third rule, and it hides in the corners where four cells nearly meet. At every grid point, the loop either does not touch the point at all, or it passes through it using exactly two sides. It can never stop dead at a point, and it can never fork into three. This quiet rule does a huge amount of work. The moment two lines meet at a point, the other sides at that point are ruled out. The moment one line reaches a point and two of the other sides are ruled out, the last side is forced to be a line. Whole chains of a puzzle fall to this rule alone.

Playing is simple. Tap any edge of the grid and it cycles: blank, then a line, then a small cross, then blank again. The cross is a note to yourself — it means you have decided the loop never runs there, and it costs nothing. You can also drag along a row of edges to draw a run of lines in one stroke, which is how big puzzles stay fast on a phone, and dragging from a line rubs a run back out. A number turns green the moment its sides add up exactly, and red if you draw one side too many, so the board always tells you where you stand. There is no timer pressure and no way to break the rules by accident: a wrong line is just a line you will move later.

Here is the solving idea in one small picture. Find a 0 anywhere on the grid and cross out all four of its sides. Now look at any 3 that touches one of those crosses: one of its sides is already ruled out, so its other three sides must all be lines. Draw them, and the corners at their ends each gain a line. At each of those corners the loop must leave by one more side, and the search narrows again. Cuts like these, chained together from one number to the next, are the entire game. No guessing is ever needed, because every puzzle here has exactly one solution.

Action	Phone / tablet	PC / laptop
Cycle an edge	Tap the edge: blank, line, cross, blank	Click the edge: blank, line, cross, blank
Draw a run of lines	Drag along the edges	Drag along the edges
Rub out a run	Drag starting on a line	Drag starting on a line
Take back a stroke	Tap the Undo button	Click the Undo button
Check your marks	Tap the Check button	Click the Check button
Take a hint	Tap the Hint button	Click the Hint button

The beginner pattern cheat sheet

Slitherlink looks open-ended, but the same small patterns appear in every puzzle ever made, and each one hands you free marks before you have done any real thinking. Learn these six and the opening of any grid, from a 5×5 Starter to a 10×10 Expert, will start to solve itself. The patterns are pure logic: each one follows from the rules alone, on every board, every time.

Pattern	What you can mark straight away	Why it works
A 0 cell	Crosses on all four sides	The cell promises zero loop sides, so every side is ruled out at once
A 3 in a corner of the grid	Lines on the two outer sides, the ones that meet at the corner point	The loop must hug the corner: any route that skips an outer side strands the corner point
A 1 in a corner of the grid	Crosses on the two outer sides	A line on an outer side would trap the corner point with only one way in and no way out
A 3 touching a 0	Lines on the other three sides of the 3	The shared side is already a cross from the 0, and the 3 still needs three lines
Two 3s side by side	Lines on the shared side and on the two outer sides parallel to it	Each 3 needs three lines, and the corners between them force the shared side first
Two lines meeting at a point	Crosses on every other side at that point	The loop passes through a point exactly twice or not at all, so the point is full

Read the table the way a solver reads it. The 0 is the loudest cell on the board: it speaks first, and everything it touches gets easier. Corner numbers are gifts because the grid edge does half of their work for them. And the last pattern, the full point, is the engine of the whole game — every line you draw closes a point somewhere, and every closed point pushes the loop somewhere new. When you are stuck, do not stare at the numbers. Walk the points instead: find a point with one line and two crosses, and the last side there is a line you have not drawn yet.

Sizes and difficulty tiers

The set puzzles come in four tiers of ten, and the climb is honest. Starter teaches the rules on a small 5×5 board where every number is close to its neighbours. Classic grows to 7×7, the size the Daily Loop uses. Tough moves to 8×8 and opens once you hold 30 stars, and Expert is the full 10×10 board, opening at 70 stars. The bigger boards are not just longer: with more blank cells, the loop has more room to hide, and the chains of logic run three and four steps deep.

Tier	Grid	Opens	Best for
Starter	5×5	Always open	Learning the loop rule and the corner patterns
Classic	7×7	Always open	A relaxed daily-style solve of a few minutes
Tough	8×8	30 stars	Longer chains and heavier cross work
Expert	10×10	70 stars	Patient solvers who want the full workout

Every puzzle in every tier has exactly one solution. That is a promise, not a hope. We build each puzzle by first growing a true single loop, then reading the numbers off the loop, then asking our own solver to count the solutions of the numbered grid. Clues are removed one at a time, and a clue stays removed only while the count stays at exactly one. A puzzle ships only when the final count is one, and the same check runs on your device for every Daily. That means you never need to guess in our Slitherlink. If you are stuck, the answer is never a coin flip. There is always a logical next step, and finding it is the game.

The Daily Loop

Alongside the set puzzles there is one Daily Loop. A fresh 7×7 puzzle arrives every day, built from the date itself, so every player in the world gets the same grid on the same day. Solve it and your streak grows by one day. Miss a day and the streak restarts at one, so the gentle pressure is real. The Daily is a Classic-size board: big enough for a satisfying chain of deductions, small enough to finish with your morning coffee.

The Daily is generated on your device the moment you open it, from a seed made of the date alone. The generator grows the day's loop and strips its clues with the same solver checks as the set puzzles, keeping the clue set only while the solution count stays at exactly one. Same date, same puzzle, on every phone and every PC. Yesterday's Daily is gone when the new day starts, so each date is a one-time meeting. Come back tomorrow and a new grid will be waiting.

Stars, Check and hints

Each set puzzle pays up to 3 stars, and the rule is simple to state and hard to earn. Finish with no hints used and no wrong Checks and you earn 3 stars. Use at most one hint and at most one wrong Check and you earn 2 stars. Any other finish earns 1 star. The Daily Loop has no stars; it pays in streak days instead, and a replay of a solved Daily still counts for practice, not for a second streak day.

The Check button is free and you can press it as often as you like. It counts every mark you have made — lines and crosses together — and tells you how many of them are wrong, but it never tells you which ones. That design is on purpose. A Check that pointed at the exact edge would do the solving for you. A count keeps the pressure honest: you know an error is on the board, and the numbers will tell you where if you read them closely. A Check that finds at least one wrong mark counts as a wrong Check for the star rule, even though pressing Check itself costs nothing.

The Hint button draws one correct loop edge for you, in the first spot where the loop is still missing. You get 3 hints per puzzle. Hints are the pressure valve for the one chain you cannot crack, but each one lowers your star ceiling, so the clean solve stays the true win. Choose your moment: a hint spent late, on a nearly finished grid, often unlocks three or four edges at once as the points around it fall into place.

7 tips to solve Slitherlink faster

1. Start with the 0s and the corners. Cross out every side of every 0, then take the free marks the corner numbers hand you. A minute of pattern work at the start can place a quarter of the loop.
2. Walk the points, not the numbers. When the numbers stop talking, scan the grid points instead. A point with one line and two crosses forces its last side to be a line, and a point with two lines closes every other side there.
3. Never let the loop branch or close early. If a line would give a point three sides, it is a cross. If a line would seal a small loop while numbers elsewhere are still unhappy, it is a cross too. The finished loop is one, and it visits everywhere it needs to.
4. Use crosses as seriously as lines. A cross is half a deduction: it pushes the loop somewhere else. Mark the edges you rule out, especially around 0s and full points, and the board stays readable at a glance.
5. Read pairs of numbers together. Two numbers that share a side or a corner talk to each other. A 3 beside a 0 gives away three lines. Two 3s side by side give away their shared side. Hunt for touching numbers before lone ones.
6. Count the green numbers. A number turns green when its promise holds. If most of a region is green except one cell, the loop near that cell is where your next marks live. Work the unhappy neighbourhoods, not the happy ones.
7. Check with a plan. If Check says two marks are wrong, do not scrub the board at random. Wrong marks travel in pairs along the loop: a line drawn in the wrong place usually means a cross sitting on a true edge nearby. Re-read the numbers around your last few moves.

Slitherlink FAQ

Is Slitherlink free to play?

Yes. Slitherlink is 100% free: the Daily Loop and all 40 set puzzles are included. You play right on this page, with no download, no sign-up and no payment.

How do you play Slitherlink?

Draw one single loop along the edges of the grid. Every numbered cell must end up with exactly that many of its four sides in the loop: three sides for a 3, none for a 0. Cells with no number are free. Tap an edge to cycle it between blank, line and cross, or drag to draw a run of lines. You win when every number is satisfied and all your lines form one loop.

Does every Slitherlink puzzle here have exactly one solution?

Yes. Before a puzzle ships, our solver counts its solutions from the numbers alone. A puzzle is used only when the count is exactly one, and the Daily Loop is generated on your device with the same check. You never need to guess: there is always a logical path to the single solution.

What is the Daily Loop?

The Daily Loop is one fresh 7×7 slitherlink puzzle per day, the same for every player, built from the date alone. Solve it to grow your daily streak. A new puzzle arrives at midnight your time, and yesterday's puzzle is replaced.

Do Check and hints cost anything?

Check is free and unlimited. It tells you how many of your marks are wrong, never which ones. A Check that finds a wrong mark counts against your stars. Hints draw one correct loop edge, you get 3 per puzzle, and each hint used lowers the stars you can earn on that puzzle.

Does Slitherlink save my progress?

Yes, in your own browser. Stars, best times, your streak and solved Dailies save automatically, and a puzzle you leave half finished is restored exactly where you left it when you come back. Nothing leaves your device and there is no account to make.

A note on the name: Slitherlink is a classic puzzle format that was first published by Nikoli in Japan. This page is an independent, unofficial GameOLL game: every grid here is original, generated by GameOLL's own software, and this site is not affiliated with Nikoli.

Last updated: November 8, 2026. Slitherlink v1.0 — the first release of our original loop-drawing game, with a Daily Loop, 40 set puzzles in four sizes, solver-proven single solutions, drag drawing, cross marks, free Check, hints and star ratings. An original GameOLL browser game. Found a bug? Tell us in the comments and we will fix it in the next version.