Hashi

About Einstein hashi

Up to 20×20 grids with 35 to 60 islands. Einstein-certified puzzles are verified solvable with logic alone, no backtracking. The deduction chains run long and require you to hold multiple constraints in mind simultaneously.

If you've solved every expert puzzle and want more, this is the end of the line. The grids are the largest we generate, and each one was verified by our constraint propagation solver before publication.