Sudoku University

Sudoku University is a solver, trainer, and generator built around a single idea: a hint should teach you the argument, not just point at a cell.

Every hint unfolds in stages. First the premise. Then the marks it depends on. Then the region it lives in. Then the eliminations. And finally the full argument in plain English. Take a hint whenever you want, skip straight to the answer whenever you want — the engine walks the same steps whether it's helping you find a Naked Single or working through a Two-String Kite.The full technique ladder