Medium Sudoku
Medium sudoku here is thirty-two or thirty-three clues with exactly one solution. It is the level where scanning for singles starts to stop being enough: about one medium grid in ten asks you to notice that a digit is confined to one row within a box, or one box within a row, and to eliminate candidates elsewhere. Pointing pairs and box-line reduction are the two techniques that break those grids open.
New puzzle generates a fresh grid at the level you last chose, Hint fills one square and names the single it used — a naked single if a cell has one candidate left, a hidden single if a digit has one home left in a unit, and otherwise it simply reveals the answer, which happens on about a fifth of hard grids and a third of expert ones. The three-dot menu at the end of the bar holds pencil marks, fill-in-all-marks, check-as-you-go, today’s shared puzzle and the difficulty level.
Your statistics · medium
- Played
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- Won
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- Win rate
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- Streak
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- Best streak
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This level
32–33 clues. Singles still finish about nine grids in ten; the rest want a pointing pair or box-line reduction.
Keyboard
- Arrows
- Move the selected cell
- 1 – 9
- Enter a digit
- Backspace
- Clear the cell
- P
- Pencil marks on or off
- F
- Full screen
- Clues
- 32–33
- Techniques
- Singles on 9 grids in 10, else pointing pairs
- Solutions
- Exactly one, verified
- Symmetry
- 180° rotational
What techniques does a medium sudoku need?
Two, mostly, and they are two halves of the same idea — that a digit's possible positions tell you as much as its actual ones:
- Pointing pair or triple. If within one box a digit can only go in cells that all share a row, then it must be in that row somewhere in that box — so it can be eliminated from the rest of that row.
- Box-line reduction. The mirror image: if within one row a digit can only go in cells that all sit in a single box, it can be eliminated from the rest of that box.
Neither fills in a cell directly. Both remove candidates, and the removals cascade into a single somewhere else. This is the level at which pencil marks stop being optional.
Are medium sudokus guaranteed to need those techniques?
No, and we would rather say so than pretend — in fact the measurement goes the other way. The generator targets a clue count and proves that exactly one solution exists; it does not classify the puzzle by the techniques required. Across a 200-seed sample, naked and hidden singles alone finished 182 of 200 medium grids, so it is the minority that genuinely demands a pointing pair. Clue count is a proxy for difficulty, and a loose one.
How do pencil marks help at this level?
They are what make elimination visible. Press Fill marks and every empty cell shows its remaining candidates; from there a pointing pair is something you can see rather than something you have to hold in your head. Entering a digit automatically strips it from the candidates of every peer, so the marks stay honest as you go.
Medium Sudoku questions people ask
- How many clues does a medium sudoku have?
- Thirty-two on most grids and thirty-three on the rest, against forty for easy and twenty-seven to twenty-nine for hard. Fewer clues generally means more work, though the relationship is loose — clue count is a proxy for difficulty, not a measure of it.
- What is a pointing pair in sudoku?
- When a digit's only possible cells within a box all lie in the same row or column, the digit must be in that row or column inside the box — so it can be removed as a candidate from the rest of that row or column outside the box.
- Should I do medium sudoku or hard?
- Medium until pointing pairs and box-line reduction are automatic. Hard adds naked and hidden pairs and triples on top, which is a genuinely different kind of looking.
- Do you need to guess on a medium sudoku?
- No. Every puzzle has exactly one solution and a logical path to it. If you find yourself guessing, there is an elimination you have not spotted.
The full rules of sudoku
This page is one rule set. The complete rules, with worked examples and the questions beginners actually ask, are on how to play sudoku, and every rule set is switchable on the main sudoku page.