What is a hidden pair?
A hidden pair occurs when two candidate digits are restricted to the same two cells in one unit.
Pure Sudoku
Intermediate technique
Hidden pairs lock two digits into two cells.
If two digits appear as candidates in exactly the same two cells of a unit, those cells must hold the pair—even when extra notes hide it.
- Level
- Intermediate
- Pattern
- Two digits restricted to two cells
- Outcome
- Logical progress
Focused example
Digits 2 and 8 appear only in the two highlighted cells.
The highlighted cells show the exact scope of the pattern. Read the candidates before making an elimination.
How it works
Apply the pattern in four checks.
- Scan one row, column, or box and count where each candidate appears.
- Find two digits that occur in the same two cells and nowhere else in that unit.
- Keep those two digits in the paired cells.
- Remove every other candidate from the two cells.
Know the difference
Use the pattern only when every condition is true.
A naked pair is obvious because the two cells contain only the paired candidates. A hidden pair is found by tracking where two digits can go across the entire unit.
After the move, re-scan the affected unit for singles before searching for another advanced pattern.
Common mistake
Protect the logic before erasing a candidate.
Apply the elimination only inside the exact shared unit covered by the pattern. Similar-looking candidates elsewhere are not part of the deduction.
If any required condition is missing, leave the candidates in place and continue scanning.
Continue playing
Choose your next Sudoku route.
FAQ
Quick answers before you play.
What can I eliminate?
Remove all other candidates from the two cells that contain the hidden pair.
Where are hidden pairs easiest to spot?
They are easiest to find in a unit with clean, complete candidate notes.
Practice loop
Find it on a live board.
Pause when the board slows down, check the candidate conditions, make one justified move, and scan again.