Medium Sudoku Online

The level where sudoku changes character. Hunting for the one cell with a single possible value is no longer enough: you have to reason about candidates and how they rule each other out. Free puzzles, no sign-up, playable offline — every one of them verified solvable by pure logic.

The step up from easy

At the easy level, you read the grid: scan rows, columns and boxes until a value forces itself. At medium, you question it. You'll reach a point where no cell has an immediate answer, and the game only moves forward by eliminating candidates deliberately. It's the shift from scanning to deduction — and it's the moment pencil marks stop being optional and become a working tool.

The tier boundary is enforced by the internal solver: a puzzle is medium if it requires at least one technique from this group, and nothing more advanced.

The techniques at this level

Three families, all built on the same idea: if a value is pinned to certain cells, it can be erased elsewhere.

The naked pair and the hidden pair: two cells in one unit that share the same two candidates between them, freeing the rest of the unit from those values. Pointing pairs: when, inside a box, a candidate is confined to a single row or column, it disappears from that line outside the box. And box-line reduction, which applies the same principle in the opposite direction — from the line into the box.

The first two families have step-by-step guides: Naked Pairs and Pointing Pairs.

Who it's for

Players who have singles down cold and want puzzles that push back — without turning into a project. A medium game demands sustained attention, but every step stays within reach: no exotic patterns, just elimination logic applied consistently.

Getting ready for hard

Once pairs and pointing become reflexes, the next step is hard sudoku: triples arrive, along with the first patterns that span several rows and columns at once, like the X-Wing. Everything you build here carries over — only the scale, and the patience required, change.