Medium Sudoku Online
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All-TimeThe medium sudoku above is fresh, free, and already waiting — tap a cell and pick up right where easy left off. This is the tier for solvers who've outgrown beginner grids and want a genuine daily brain workout: hard enough to push back, short enough to finish today and repeat tomorrow. Fewer clues mean you'll earn some placements instead of just spotting them — and that's the fun. The walkthrough below teaches the three moves that carry every medium solve, with examples you can follow cell by cell.
What makes a medium sudoku medium?
Two things separate a medium grid from an easy one. First, the head start shrinks: a medium sudoku begins with about 27 to 35 of the 81 cells filled in — fewer than the 36 to 45 an easy board hands you. Second, and this is the real definition of the tier: scanning and singles will get you started, but they will not finish the puzzle. You'll hit cells where no single resolves, however carefully you sweep — and that wall is there by design. Medium is where pencil marks and pairs earn their keep, and where real technique gets built. One promise never changes: every grid has exactly one solution, reachable by pure logic — no X-Wing, no chains, no guessing ever required at this tier.
How to get better at sudoku: the medium toolkit, step by step
Three skills carry every medium solve, and the steps below teach each with a worked example. First, candidates — the pencil marks that show what a cell can still be. Then the naked pair, which locks two digits into two cells and clears them from everywhere else — the hidden pair is its mirror image. Finally the pointing pair, which reaches outside its own box. Learn these three and medium stops being a wall.
Step 1: pencil marks — track your candidates
You already know singles from easy — pencil marks are what you do when they run out. The moment no cell resolves, stop hunting and start writing: note the digits each stuck cell could still take, small, in its corner. Don't mark all 81 cells — only the ones blocking your progress. And on this board you don't even need a pencil: the Notes toggle and Show Candidates button do the writing for you.
Step 2: the naked pair — two cells that crack two more
Look at the row below. Five digits are given — 1, 3, 7, 8, and 9 — leaving 2, 4, 5, and 6 for the four empty cells. Clues elsewhere in their columns have already trimmed the second and fourth cells to the same two candidates: 2 and 6. That's a naked pair. Those two digits must fill those two cells in some order, so you can strike 2 and 6 from every other cell in the row. Watch the cascade: the sixth cell collapses from 2, 4, 6 to a lone 4 — place it — and with 4 gone, the eighth cell reads 5. One pair, two cells cracked.
Step 3: the pointing pair — a box that clears cells outside itself
The band below shows a pointing pair at work. Look at the outlined box on the left and ask where its 5 can go. A 5 further along the middle row blocks that row's cell in the box, and another 5 further along the bottom row blocks the rest — so the box's 5 must land in one of the two highlighted top-row cells. Whichever one takes it, the box's 5 sits in the top row — so no top-row cell outside the box can be a 5, and three eliminations fall at once. The same box-and-line logic runs in reverse too; that version is called box-line reduction, and hard puzzles lean on both.
Warm up on easy, level up to hard
Medium is the middle rung, and good solvers climb in both directions. On a slow morning, or after a bruising grid, dropping back to easy sudoku for a warm-up is a smart habit, not a retreat — the ladder runs both ways, and easy keeps your scanning sharp. The step up has a clear signal too: when your medium solves routinely land near the bottom of the 10-to-20-minute band and you spot pairs without second-guessing yourself, you're ready for hard sudoku. Hard deals only about 22 to 26 givens, so the pairs you've practised here become everyday moves rather than highlights. It will also, eventually, ask for the X-Wing technique — a candidate-clearing pattern that medium never requires and hard only occasionally does.
Medium sudoku questions
How hard is medium sudoku?
Medium is the middle rung of the ladder — a real step up from easy, but well short of the grind of hard and expert. Expect a solve to take 10 to 20 minutes: long enough that you'll need pencil marks and a pair or two, short enough to finish in one sitting.
What techniques do you need for medium sudoku?
Four tools cover it: careful scanning, pencil marks to track candidates, naked and hidden pairs, and pointing pairs when a digit is confined to one line inside a box. That's the whole medium toolkit. You'll never need X-Wing, Swordfish, or chain logic here — those patterns belong to hard and above.
Do I need pencil marks for medium sudoku?
Yes — medium is the first tier where pencil marks genuinely pay for themselves. Easy hands you enough clues to keep everything in your head, so you never needed them there. Medium takes that comfort away on purpose: some cells only crack once their candidates are written down. Build the habit here and every harder tier gets easier to learn.
How long does a medium sudoku take?
Most solvers finish a medium 9×9 in 10 to 20 minutes. With about 27 to 35 givens, you'll place a handful of digits by scanning, then slow down and lean on pencil marks and elimination for the rest. It's quick enough for a coffee break but meaty enough to keep your logic engaged.
Is there a limit on how many medium sudokus I can play?
No limit at all. A brand-new medium puzzle is generated the moment you finish the last one, so a daily habit never runs dry — no quota, no countdown, no premium tier holding the good grids back. Signing in is free and turns each medium solve into 25 XP toward your level, on a board with the ads switched off.
Is medium sudoku a good daily brain workout?
It's arguably the best tier for one. A medium puzzle makes you genuinely reason — track candidates, spot pairs, follow a line of logic to its end — yet at 10 to 20 minutes it's short enough to finish every single day. That repetition is what compounds: one medium a day builds pattern recognition faster than occasional marathon sessions ever will.
Where medium sudoku takes you next
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