Discover how to use the Naked Single technique in Sudoku to solve puzzles logically. Ideal for new players seeking effective strategies.
Are you new to Sudoku and just came across the term “Naked Single”? It’s one of the simplest yet highly effective strategies to help you solve challenging cells with ease. In this article, we’ll show you how to identify and use the Naked Single technique to improve your Sudoku-solving skills quickly.
What is a naked single?
A Naked Single is a classic technique used in Sudoku. A cell is considered a Naked Single when there is only one possible number that can logically be placed in it, after you eliminate all other numbers that already appear in the same row, column, and 3×3 box.
When should you use the naked single technique?
This technique is typically used:
- At the early stages of a puzzle, when you’re scanning for easy placements.
- After placing a number, to reassess the remaining empty cells.
- When you want to avoid guessing and rely purely on logic.
Step-by-step guide to using naked singles
Step 1: Identify empty cells
Scan the Sudoku board and locate all the cells that haven’t been filled yet.
Step 2: Check the numbers already present in the same row, column, and 3×3 box
For each empty cell, list all the numbers from 1 to 9 that have not yet appeared in its row, column, and box.
Step 3: Find cells with only one valid candidate
If a cell has only one remaining possible number, that’s a Naked Single → Go ahead and fill it in.
Step 4: Update the board and repeat
Every time you place a number, update the list of candidates for the remaining empty cells. This often reveals new Naked Singles you can solve next.
Quick example
Let’s say you’re looking at an empty cell. After checking the related row, column, and 3×3 box, you eliminate the numbers:
1, 2, 3, 4, 5, 6, 8, and 9
The only number left is 7 → This is a Naked Single.
You can confidently fill in 7 without any guessing.
Why is the naked single technique important?
- It’s 100% logical and error-free — no guessing required.
- Ideal for beginners learning Sudoku strategies.
- It can unlock other cells when combined with more advanced techniques like Hidden Singles, Naked Pairs, or Pointing Pairs.
Practice naked singles in a free Sudoku game
Want to try out the Naked Single technique right now?
Play Sudoku for free right here
Choose from different difficulty levels and get step-by-step hints if you get stuck!
The Naked Single technique is one of the most useful tools in solving Sudoku puzzles. Mastering and practicing it regularly will help you solve puzzles faster and more accurately – even at higher difficulty levels. Start with this method and gradually take on more challenging logic puzzles step by step!
