WELCOME TO SWITCHYARD
Every number has a part to play.
Build one continuous railway between the fixed A and B tracks. Each number tells you exactly how many squares contain track in that row or column, including the stations.
Tracks can turn or go straight. They cannot branch, cross, form loops, or run off the board except at the two marked endpoints. Other squares stay empty.
Use a red × for a square you think is empty, or a green dot for a possible track. These are notes, and do not count as track.
S StraightC CornerR RotateX Empty noteD Maybe note⌫ Erase square
Use arrow keys to move around the grid and Enter or Space to place your tool. Click a placed corner to rotate it, or use R on a selected track. Corners avoid walls, X marks, and rails that cannot connect. Press Erase to clear the selected square. Select a toolbar tool again to replace a track. Ctrl/Cmd + Z undoes a move; Shift + Ctrl/Cmd + Z redoes it.
A check beside an edge number means its track count is met. Click that number to mark its remaining blank squares empty; existing notes stay in place. The whole action can be undone together.
Hint explains one deduction and highlights the relevant squares. Apply hint is optional. Hints assume your tracks and X marks are correct. Solve the route to send a little train from A to B; reduced-motion mode shows its arrival without movement.
The timer starts when you load a puzzle, continues while you are away, and stops when solved. Reset starts the timer again. Share / Scan creates a QR code for the same starting puzzle; the other player gets their own board and timer. Camera scanning requires HTTPS and camera permission.
Difficulty reflects the alternatives explored by our puzzle solver. Every puzzle has exactly one solution. Check reports rule conflicts, but won’t give away the route.