GridZero
MediumChallenge

Preparing your puzzle…

Keyboard: 1–9 to enter · N for notes · arrows to move · ⌘/Ctrl+Z to undo.

New puzzle

Your kind of puzzle

Collection puzzles use published difficulty ratings. Generated puzzles are graded by the deductions needed to solve them.

How you play

8,000 rated, uniqueness-checked puzzles. No downloads needed.

Your current puzzle is replaced only when the new one is ready.

Settings

Make it yours

System follows your device. Scheduled uses your local clock, never your location.

New puzzles

Strike limits apply to new games. Your current game's rules stay consistent.

Optional assistance

Notes are manual by default. Assistance uses only the current board, never the hidden solution. Undo restores the entire move.

While you play

Free, open source, and offline-ready. No ads. No tracking. No accounts. 8,000 collection puzzles courtesy of Grant McLean / Sudoku Exchange, generated with QQWing and rated with Sukaku Explainer. Public domain. Browser and native saves are separate.