Medium Sudoku — Play Free Online
Free medium Sudoku puzzles, playable in the browser with no sign-up. Around 34 clues to start, and the first level where pure scanning runs out before the grid does — you will need to think about where a digit can go in a unit, not just what can go in a square.
- Clues to start
- about 34
- Par time
- 12 min
- Cost
- free, no sign-up
What changes at this level
Medium grids open like easy ones. A dozen squares fall quickly, and then the board goes quiet: you sweep all nine digits, find nothing, and sweep again. That silence is the level working as designed, not a sign you have made a mistake.
What breaks it is a change of question. Instead of asking what can go in a square, you ask where a given digit can go in a given row, column or box. Often the answer is one place, even though that square could have accepted two or three other digits. That is a hidden single, and it is the technique this level is built around.
The most-played level
Medium is where most people settle, and it is the default the board starts on. It is long enough to feel like a puzzle and short enough to finish in one sitting — the par time here is 12 minutes, and beating it earns a speed bonus on your final score.
This is also the level where pencil notes start earning their keep, though not everywhere at once. The medium guide covers how to use them on one unit at a time instead of filling in the whole grid.
If it feels too hard, or too slow
Stalling repeatedly usually means hidden singles have not clicked yet, not that you need a gentler puzzle — spend a few grids on easy Sudoku to get the scanning automatic, then come back. If instead you are finishing without ever getting stuck, go straight to hard Sudoku.
Other levels
- Easy Sudoku — about 42 clues.
- Hard Sudoku — about 28 clues.
- Expert Sudoku — about 24 clues.
- How to play Sudoku — the rules, plus a separate guide for each level.