Naked Pairs in Sudoku: How to Spot & Eliminate Pair Candidates

By Avi Israeli · Reviewed by Ninely Engine Logic Council · Updated November 2026

What is a Naked Pair?

A Naked Pair occurs when exactly two cells inside the same unit (a row, column, or 3×3 box) contain the identical pair of candidate digits, say {X, Y}, and no other candidates.

Because those two digits must occupy those two cells in some order, neither digit can appear anywhere else in that unit. You can safely eliminate X and Y from every other empty cell in that row, column, or box, often leaving a Naked Single behind!

Worked Example: Naked Pair {3, 4} in Row 8 Unlocks Cell R8C9

Look at Row 8 on the board below. Six digits are already firmly solved: R8C1 = 2, R8C2 = 5, R8C3 = 8, R8C4 = 1, R8C6 = 7, and R8C8 = 9. The row is missing only three digits: {3, 4, 6}.

  • Cells R8C5 & R8C7: Both empty cells see 6 in their intersecting columns and boxes, restricting their pencil marks strictly to {3, 4}. They form a textbook Naked Pair.
  • Target Cell R8C9: Cell R8C9 in Box 9 sees 4 in its column, leaving candidate notes {3, 6}.
  • Elimination: Because 3 and 4 are locked into R8C5 and R8C7 along Row 8, candidate 3 is eliminated from R8C9. This leaves 6 as the sole legal candidate!
Naked Pair (R8C5 & R8C7)
3 4
3 4
➔
Target Cell R8C9 (3 Eliminated)
3 6
7
8
6
6
9
5
8
2
6
1
4
7
8
9
2
1
1
9
6
3
5
2
4
3
7
6
9
1
5
2
5
8
1
34
7
34
9
36
1
4
6
Step 2 of 3: {3, 4} form a Naked Pair along Row 8, locking both digits into those two cells

⚠️ The Tempting Wrong Move: Guessing 3 in R8C9

A player looking casually at Box 9 sees that R8C9 can take 3 or 6 and might be tempted to guess 3.

Why this fails: Placing 3 in R8C9 eliminates 3 from both R8C5 and R8C7 along Row 8. That forces both cells to become 4 simultaneously, causing an immediate conflict in Row 8! Spotting the Naked Pair first prevents this fatal error.

💡 Solving Tip: The Twin Candidate Scan

When solving intermediate puzzles with candidate notes, regularly scan each house for cells that contain exactly two pencil marks. When two cells in the same line or box share the exact same two digits, immediately draw a mental boundary around them and prune those two numbers from every neighboring peer.

Ready to Spot Naked Pairs?

Test your candidate reading skills on today's free daily puzzle:

Play Today's Daily Warmup ➔