🕸 Untangle
Puzzle / Logic · Free online · No download · No sign-up
Untangle presents a graph: a set of dots (nodes) connected by lines (edges) in a tangled mess. Your task is to drag the nodes to new positions until no two edges cross. There is always a solution — every puzzle generated is a planar graph, meaning a crossing-free layout exists — but finding it requires spatial reasoning that goes well beyond simply shuffling nodes around and hoping. The first few nodes settle easily; the last few require genuine insight about the topology of the graph.
How to play Untangle
- Observe the tangled graph. Crossing edges are shown in red; uncrossed edges are shown in white.
- Drag any node to a new position. Edges update in real time.
- Your goal is to eliminate all red crossings — a solved graph has no red edges.
- Nodes can be placed anywhere on the board; there are no grid restrictions.
- The puzzle is complete when every edge is white (uncrossed).
- Fewer total moves to reach a solved state earns a better efficiency score.
Tips to beat your high score
- Find the outer ring first. In most planar graphs, a clean solution has a ring of nodes around the outside and interior nodes nested inside them. Identify which nodes could form that outer ring — usually the ones with fewer edges — and place them on the boundary of the board first.
- Follow one chain at a time. If you trace a path from node A to node B to node C through the edges, those three nodes should lie in a roughly straight or gently curved line in the final solution. Use this to group connected chains into smooth arcs.
- Move high-degree nodes last. Counter-intuitively, once a high-degree node is placed, moving it disrupts many edges at once. Place it in roughly the right location early but make only fine adjustments at the end.
- Look for triangles and squares. Three nodes that form a triangle in the edge list should form a triangle in the layout. Four nodes that form a square in the edge list should form a quadrilateral. Recognising these substructures and placing them correctly simplifies the larger puzzle.
- Use crossing count as a progress metric. The number of red crossings should decrease monotonically as you improve. If a move increases the crossing count, undo it immediately rather than hoping the new arrangement will untangle elsewhere.
What this game trains your brain to do
Untangle is a direct exercise in graph topology — reasoning about how a network of connections is structured independently of where its nodes are physically placed. The mathematical question of whether a graph can be drawn without edge crossings (planarity testing) is a problem that computers solve in linear time, but humans use a qualitatively different approach: visual heuristics, pattern recognition, and mental rotation rather than formal algorithmic search.
The spatial skills exercised by Untangle — mentally rotating a graph, reasoning about connectivity without following each edge, predicting how moving one node will affect crossing counts elsewhere — overlap significantly with the skills used in reading circuit diagrams, understanding molecular structure, planning network architecture, and playing strategy board games. Regular practice on graph-based puzzles is associated with improvements on standardised tests of spatial reasoning and visual-spatial working memory.
About Untangle
Untangle is a deceptively simple puzzle format that has attracted a dedicated community of enthusiasts who compete for minimum-move solutions on large graphs. CrizBrain’s version generates graphs of increasing complexity, starting with manageable five-node puzzles and progressing to dense twenty-node tangles that require genuine graph intuition to solve.
Like all CrizBrain games, Untangle runs entirely in your browser with no account and no data sharing. Your best completion stats are saved locally on your device. Each puzzle is procedurally generated, so there are always new challenges waiting regardless of how many times you have played.