Sudoku Solving Techniques for Beginners
The three Sudoku techniques that solve most easy and medium puzzles. Skip the wall-of-jargon guides and start here.
Most Sudoku technique guides throw fifteen named strategies at you on day one. You don't need fifteen. You need three. These three techniques will solve almost every easy and medium Sudoku you'll ever see.
1. Naked single ("only choice")
Look at each empty cell. If eight of the nine possible digits are already in that cell's row, column, or 3×3 box, the ninth digit is the answer. This one technique solves most easy puzzles by itself.
2. Hidden single ("only place")
Pick a digit — say 5. Look at each 3×3 box. If there's only one empty cell in that box where 5 could legally go (because every other empty cell already has a 5 in its row or column), that cell is a 5.
3. Pencil marks
For every cell you can't immediately solve, note the digits that could legally go there. This turns the puzzle from "guess and check" into a system you can reason about. Almost every technique beyond naked/hidden singles is a pattern in pencil marks.
What comes next
Once these three are automatic, learn "pointing pairs" and "naked pairs" — see our Sudoku strategy guide and how to solve Sudoku faster for the next steps.
Practice
Play today's Sudoku daily puzzle. Start on Easy or Medium and apply naked singles first, hidden singles second. Every solve reinforces the pattern.
Frequently asked questions
What is the easiest Sudoku technique for beginners?
The 'naked single': if a cell has only one possible digit given its row, column and box, that digit is the answer. This alone solves most easy puzzles.
How many Sudoku techniques do I actually need?
Three: naked singles, hidden singles, and pencil marks. That covers nearly every easy and medium puzzle.
What are pencil marks in Sudoku?
Small notes in each empty cell listing the digits that could legally go there. They turn Sudoku from guessing into logical elimination.
Do I need advanced techniques for medium puzzles?
Rarely. Medium puzzles are almost always solvable with the three beginner techniques applied carefully.
Where can I practice Sudoku for free?
Play the daily Sudoku free at puzzletheory.fun/games/sudoku — four difficulty levels, no signup.
Play a puzzle
Put the ideas from this article into practice with today's daily challenge — or browse all our games.