Net Puzzles
Rotate every scrambled tile until the pipes join into one unbroken network with no loose ends anywhere on the board.
Hints available. Play as many boards as you like.
Ready when you are.
Scan to open on a phone
Scan for the same board — no hints.
How to play
Each cell holds a piece of pipe with connectors on some of its four sides. Tap or click a cell to turn that piece one quarter clockwise; shift-click or right-click turns it back.
The board is solved when every connector meets a connector on the neighboring cell, no connector points off the edge of the grid, and every cell is joined to the source in the top-left corner.
Live pipe is drawn in the bright color and dead pipe in gray, so the network visibly grows out of the source as you work. Arrow keys move the cursor and space turns the piece under it.
Strategy
Start at the edges. A cell in the top row cannot point north and a corner cannot point north or west, so its piece often has only one rotation that is even legal — those are free moves that need no reasoning at all.
Work outward from what is already forced. Once a piece is fixed, every neighbor learns something: a face with pipe against it must accept pipe, and a face with a blank against it must not offer any.
Remember that the network is a tree, so it never closes a ring. If turning a piece would complete a loop, that rotation is wrong even though every connector in it appears to match.
Leave the straight pieces and the four-way crosses until last. They look the same after a half turn and a quarter turn respectively, so they tell you least and are the cheapest to fix once their neighbors are settled.
Difficulty and variants
Difficulty is grid size and nothing else: easy is 5x5, medium 7x7 and hard 9x9, rising to 7x7, 9x9 and 11x11 where the screen has room. Every board is a spanning tree of its grid, so a bigger board is more of the same reasoning rather than a different kind of it.
Questions, answered
Is every Net puzzle solvable?
Yes. Each board is built by carving a random spanning tree of the grid and then spinning the pieces, so the unrotated arrangement is always a valid answer — the puzzle is only ever to find it again.
Can a Net board have two solutions?
Not in any way that matters. The layout is forced, and the only freedom is that a straight piece looks identical after a half turn and a cross after a quarter turn. The board judges the picture you have made rather than the number of taps, so those rotations count as correct.
Why is part of my network gray?
Gray pipe is not yet joined to the source in the top-left corner. It may already be correctly rotated and simply waiting on a cell between it and the source, so gray is a hint about where to look, not a verdict on that piece.
What do the small squares mean?
A square marks a terminal — a piece with a single connector, the end of a branch. The ringed disc in the top-left corner is the source every other cell must eventually reach.
Are the boards the same for everyone?
Each board is generated from a seed, so the same seed always produces exactly the same grid on every device. New Puzzle draws a fresh seed.