Untangle Puzzle Games: Free Planarity-Style Games to Play Online
Untangle games ask you to drag points until no lines cross. Here's how the genre works, why it trains spatial reasoning, and where to play a free daily one.
Untangle puzzles — sometimes called planarity games — hand you a tangle of points joined by lines and ask a single question: can you drag the points around until no two lines cross? There are no words, no numbers, and no instructions to read. It's one of the purest logic genres on the web.
Where the genre comes from
The idea comes from graph theory. A graph is planar if it can be drawn on a flat surface with no edges crossing. Untangle games generate a graph that is guaranteed planar, then scramble the layout so it looks impossible. Every puzzle you see has a clean solution — that's the promise the generator makes.
1. Knot — our daily untangle puzzle
Knot drops a fresh tangle every day. Drag points with mouse or finger, watch crossing lines highlight in real time, and the puzzle completes the moment the last crossing clears.
What you get: guaranteed-solvable layouts, difficulty tiers that add nodes and edges, a solve timer for speed-runs, and a 30-day archive for members. No adverts interrupting a drag.
2. Domino Regions — constraint logic
If you like wordless logic, Domino Regions is the other end of the spectrum: place dominoes so every region's sum, equality and comparison constraint is satisfied. See our domino puzzle games guide.
3. Sudoku — the classic
Sudoku needs no introduction. If untangling appeals because it's pure deduction with no vocabulary, Sudoku is the same pleasure in a grid. Start with solving techniques for beginners.
4. Recall — spatial memory
Recall flashes a pattern and asks you to repeat it, adding one tile per round. It exercises the same visual-spatial channel as untangling, from the memory side.
5. A wordless logic set
Knot, Domino and Sudoku together make a nice no-language rotation — useful if English isn't your first language or you simply want a break from words. More options in free online logic puzzles.
Strategy: how to untangle fast
- Find the outer ring. Most planar graphs have a natural outside boundary. Push high-degree nodes outward first.
- Spread, don't shuffle. Widen the whole layout before fixing individual crossings; crowded points create false crossings.
- Work one node at a time. Drag the node with the most crossings and park it far away, then bring it back in.
- Untwist pairs. Two lines crossing usually means two endpoints are swapped. Trade their positions.
Where to go next
- Try it yourself in Sudoku, or jump straight to today's board.
- Browse more logic puzzles in the same family.
- Go deeper with our best daily puzzles list.
- Missed a day? Pro members can replay the last 30 daily challenges.
Frequently asked questions
What is an untangle or planarity puzzle?
It's a logic puzzle where points are joined by lines and you drag the points until no two lines cross. Every puzzle is generated from a planar graph, so a crossing-free layout always exists.
Is there a free daily untangle game?
Yes. Knot is a free daily untangle puzzle with a new tangle every day at UTC midnight, plus unlimited practice mode.
Are all untangle puzzles solvable?
In Knot, yes. Each puzzle is built from a graph that is planar by construction and then scrambled, so a crossing-free arrangement is guaranteed.
Do untangle games improve spatial reasoning?
They give sustained practice at mentally rotating and rearranging layouts, which is the core of visual-spatial reasoning. Like any training, the gains are strongest in tasks that resemble the game.
Can I play Knot on a phone?
Yes. Points are dragged with touch, and the board scales to the screen so nodes stay comfortably large on mobile.
Ready to play?
Seven free daily puzzles — word, number and logic. No signup, no ads in your way.