How to Find & Solve Naked Pairs in Sudoku
A Naked Pair is one of the most powerful and fundamental solving strategies in intermediate Sudoku. Spotting it unlocks stalled boards by removing impossible candidates from neighboring cells.
Hands-On Naked Pair Elimination
In Row 5, examine the two highlighted cells (R5C3 and R5C5). Both contain exclusively {3, 7}. Observe how this eliminates 3 and 7 from R5C8, leaving digit 4 as a naked single!
The 3-Step Naked Pair Rule
- Scan a Single House (Row, Col, or Box): Look for two cells that contain the exact same pair of candidate numbers (e.g.
[3, 7]and[3, 7]) with no other candidates. - Apply the Pigeonhole Principle: Since two cells must contain these two digits, neither digit can appear anywhere else in that same unit.
- Eliminate Candidates: Erase those two numbers from the candidate lists of all other cells sharing the unit.
Frequently Asked Questions
What is a Naked Pair in Sudoku? ▼
A Naked Pair occurs when two cells in the exact same unit (a row, column, or 3×3 box) contain the identical two candidate numbers, and no other candidates. Because those two numbers must occupy those two cells, they can be safely eliminated from all other cells in that unit.
How does finding a Naked Pair help solve the puzzle? ▼
Finding a Naked Pair prunes candidate numbers from neighboring cells in the same row, column, or box. This elimination frequently creates Naked Singles or Hidden Singles, unblocking the rest of the board.
Can a Naked Pair exist across different 3×3 boxes? ▼
Yes, as long as both cells share the same row or the same column. If both cells also happen to lie within the same 3×3 box, the elimination applies to the entire box as well as the row/column.
Put Naked Pairs into Action
Ready to spot Naked Pairs in real puzzles? Practice your candidate elimination skills on our Medium Sudoku or Hard Sudoku boards, or advance to the next strategy in our learning silo.