Medium Sudoku asks a bit more of you. Plain scanning stops being enough on its own — you'll start tracking candidate digits and spotting when a digit is only possible in one cell of a row, column, or box, even if that cell still looks busy with other candidates.
Medium is where Sudoku starts to feel like a puzzle rather than a checklist — the first tier where taking notes genuinely pays off.
Every puzzle here is generated to require specific solving techniques, not just picked at random — this is what medium actually means on Ranked Sudoku:
Most Sudoku sites end at the puzzle. Ranked Sudoku doesn't: a solve you finish here — even before signing up — can become an opponent for someone else to race. Create a free account and you can race real players' recorded solves yourself, beat their time, and climb an ELO rating that tracks how you're actually improving, not just a streak counter.