What is a naked pair in sudoku?

A naked pair is two cells in the same row, column, or box that each contain exactly the same two candidates and nothing else — for example both showing only {3, 7}. Those two cells will use up 3 and 7 between them, so 3 and 7 can be erased from every other cell in that unit.

What's the difference between a naked pair and a hidden pair?

A naked pair is two cells that hold only the same two candidates — you erase those digits from the rest of the unit. A hidden pair is two digits that can only appear in the same two cells, even though those cells list other candidates — you erase every other candidate from those two cells. Naked looks at the cells; hidden looks at the digits.

Does a naked pair place a number?

No. A naked pair is an elimination technique — it removes candidates rather than placing a digit. Those eliminations usually expose a hidden or naked single on the very next scan, which is the move that actually fills a cell.

Difficulty tier T2

Naked Pairs in Sudoku: Spot Them, Eliminate

The naked pair is the jump from beginner to intermediate: your first move that doesn't place a digit but instead clears the way for one. Once you see pairs, boards that felt stuck start opening up.

What a naked pair is

A naked pair is two cells in the same unit (row, column, or box) that each contain exactly the same two candidates and nothing else — say both show only {3, 7}. You don't know which cell is the 3 and which is the 7, and you don't need to: between them, those two cells will consume both digits.

That means 3 and 7 can be erased from every other cell in that unit. Those eliminations are the whole point — they usually reveal a hidden single on your next scan.

Naked vs. hidden — don't mix them up

Pattern	You look at	What you erase
Naked pair	Two cells holding only the same two candidates	Those two digits, from the rest of the unit
Hidden pair	Two digits that fit only the same two cells	Every other candidate, from those two cells

They're mirror images. Naked pairs are easier to spot because the cells are "clean" (just two candidates). Hidden pairs hide among clutter.

Where this sits: naked and hidden pairs are tier T2 in Speedoku's difficulty model, together with pointing pairs. T2 is the first level that requires reading candidates at all — a puzzle that needs a pair is a step past pure singles.

Using them for speed

Pairs reward selective pencil marks. You don't need full candidates on every cell — just mark the cells in a unit that look tight, and the pair often pops out. Marking everything, everywhere, is the habit that actually slows solvers down.

Want reps? Practice free, or try today's Daily Challenge and see how quickly you catch the pairs.

Frequently asked questions

What is a naked pair in sudoku?: A naked pair is two cells in the same row, column, or box that each contain exactly the same two candidates and nothing else — for example both showing only {3, 7}. Those two cells will use up 3 and 7 between them, so 3 and 7 can be erased from every other cell in that unit.
What's the difference between a naked pair and a hidden pair?: A naked pair is two cells that hold only the same two candidates — you erase those digits from the rest of the unit. A hidden pair is two digits that can only appear in the same two cells, even though those cells list other candidates — you erase every other candidate from those two cells. Naked looks at the cells; hidden looks at the digits.
Does a naked pair place a number?: No. A naked pair is an elimination technique — it removes candidates rather than placing a digit. Those eliminations usually expose a hidden or naked single on the very next scan, which is the move that actually fills a cell.