Sudoku Puzzles for Adults

Daily brain training that builds logic, focus, and long-term cognitive resilience.

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72 The small number = how many of that digit are still left to place.

Tips for a satisfying solve

Scan rows, columns, boxes first. For medium difficulty, most placements come from cross-referencing two of the three unit types at once.
Use Notes for busy areas. When three or more candidates compete in a row, pencil them all in. The answer becomes visible quickly.
Don't rush. Medium puzzles are designed to be enjoyed over a coffee break. Relax mode removes time pressure entirely.
Save hints for the end. You get three; using one at a genuine dead end is much more rewarding than early.

More ways to play

Five free puzzle games, one calm hub. No account, no app.

Mini Sudoku⚡ 6×6 · 2-min Easy SudokuGreat for beginners Hard SudokuNaked & pointing pairs StrandsDaily word hunt CryptogramCrack the cipher

Why Sudoku is great for adult brains

A few minutes of logic a day is a genuine workout for memory, focus and pattern recognition.

Sharper memory

Holding candidate numbers in mind exercises working memory, the mental scratchpad you use all day.

Better focus

Sudoku rewards sustained attention. Regular solving builds the habit of staying with a problem.

Calm & flow

The quiet, deliberate pace is a low-stakes way to decompress, a small daily ritual worth keeping.

Why medium Sudoku is the adult sweet spot

Easy Sudoku gets you started. Medium Sudoku keeps you engaged. With 33–36 clues, the board has enough structure to feel solvable but enough ambiguity to require real thought. You won't need advanced techniques, but you will need to cross-reference rows, columns and boxes with intention.

What adult solvers appreciate

No time limit in Relaxed mode: solve at your own pace, no game-over anxiety.
Dark mode and large text: easy on the eyes for evening sessions.
Daily challenge: one shared puzzle per day so you can compare your time with others.
Pencil marks (Notes): just like a real newspaper puzzle but easier to erase.

Research suggests regular puzzle solving is associated with better cognitive health in adults. Whether or not you buy the science, 15 minutes of Sudoku is simply a pleasant way to start or end the day.

Frequently asked questions

Medium Sudoku has 33–36 given clues, more than easy (37–45) but fewer than hard (28–32). You'll need occasional scanning techniques beyond basic row/column/box elimination.

Research suggests regular Sudoku practice is linked to better working memory and sustained attention. The medium level provides meaningful challenge without requiring advanced techniques.

Most adults finish in 10–20 minutes. Challenge mode adds gentle time pressure, but Relaxed mode lets you solve without any game-over risk.

No. All puzzles are free with no sign-up, no app, no subscription. Your preferences are saved locally in your browser.

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Puzzle solved!

Clean board, well played.

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✦ Score

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Three mistakes

That's Challenge mode for you. Want to keep going on this same board in Relaxed mode instead?