Difficulty Levels, Explained

Our puzzles come in six levels: Easy, Medium, Hard, Expert, Master, and Grandmaster. Two things determine where a puzzle lands: how many givens (starting digits) it offers, and — more importantly — which solving techniques it demands. Every puzzle, at every level, is verified to have exactly one solution and to be solvable by logic alone. Harder never means "you have to guess"; it means the logic runs deeper.

What each level asks of you

• Easy — Around 46 givens. Solvable almost entirely with Naked Singles and simple scanning. A relaxed solve and the right place to learn the interface and build a note-taking habit.
• Medium — Around 36 givens. Hidden Singles become essential: you will need to scan digit-by-digit across rows, columns, and boxes rather than waiting for cells to empty out on their own.
• Hard — Around 29 givens. Expect to lean on candidate notes throughout, with Naked Pairs and Pointing Pairs doing real work. The first level where most solves include a genuine "stuck" moment.
• Expert — Around 24 givens. The full intermediate toolkit — pairs, hidden pairs, box-line eliminations — applied in combination, with long quiet stretches where eliminations build before anything resolves.
• Master — Around 25 givens, but graded harder than Expert: these puzzles are constructed to require advanced patterns such as the X-Wing or Swordfish. More clues, deeper logic — proof that difficulty is about technique, not just sparseness.
• Grandmaster — Around 22 givens, requiring XY-Wings and chain logic. The hardest puzzles we publish. A clean Grandmaster solve is a real achievement at any pace.

How the grading works

A puzzle is generated, digits are removed to the level's target, and the result is accepted only if it still has a single unique solution. The Master and Grandmaster levels add a technique gate: the puzzle must actually require their signature advanced moves, so you will never pay Grandmaster effort for Expert logic. This is also why Master can carry slightly more givens than Expert and still be harder — the count of clues matters less than what the clues force you to do.

Picking your level

Choose the level where you get stuck sometimes. If you never stall, move up — the satisfaction lives just past comfortable. If a level feels like a wall, drop back one and visit the Techniques guide; each level's wall is usually one specific technique you haven't met yet. Free play allows up to five mistakes per puzzle with hints available when you need a nudge, so a level slightly above your comfort zone is a safe place to learn.