Beginner Sudoku Strategy
Naked singles and hidden singles — most easy puzzles need nothing else.
Scan the grid. Fill every cell that has only one possible digit. Repeat.
Easy sudoku puzzles are solvable with two techniques: naked singles and hidden singles. Together they usually carry you through any puzzle graded "easy" without notation.
Part of: Daily Challenges
Quick answer
Scan the grid. Fill every cell that has only one possible digit. Repeat.
Key points
- ▸ Naked single: a cell where only one digit is possible given the row, column, and box constraints.
- ▸ Hidden single: a digit that can only go in one cell within a row, column, or box, even if that cell has multiple candidates.
- ▸ Scan by digit: "where can the 1 go in this box?" Often there is only one spot.
- ▸ Scan by cell: "what can go in this empty cell?" If only one number fits, fill it.
- ▸ Fill every naked/hidden single you find before moving to harder techniques.
Examples
- Naked singleA cell where the row has 2,4,7,9, the column has 3,5,8, the box has 1,3,6. Only 0 missing from 1–9 is... recheck: row+col+box covers 1,2,3,4,5,6,7,8,9 minus {unique missing} — the remaining single digit is the answer.
- Hidden singleIn a box with two empty cells, only one of them is in a row that does not already contain 4. That cell must be the 4, even if the cell itself could hold other digits by box-alone.
- Scanning drillGo 1 through 9. For each digit, check each box: "can this digit go in only one cell of this box?" Fill every one-cell case.
When to use which tool
- Easy SudokuStart here — almost every puzzle is solvable with just naked and hidden singles.Play easy Sudoku in your browser. About 36 given clues — ideal for beginners or a quick puzzle.
- Medium SudokuStep up once easy puzzles feel automatic. Add pair-based techniques.Play medium Sudoku in your browser. About 30 clues — needs light scanning and candidate elimination.
- SudokuMain sudoku hub — pick your difficulty and play.Play Sudoku in your browser. Easy, medium, hard, and expert boards. Auto-save progress.
Related
- SudokuPlay Sudoku in your browser. Easy, medium, hard, and expert boards. Auto-save progress.
- Easy SudokuPlay easy Sudoku in your browser. About 36 given clues — ideal for beginners or a quick puzzle.
- Medium SudokuPlay medium Sudoku in your browser. About 30 clues — needs light scanning and candidate elimination.
- Sudoku Difficulty ExplainedWhat actually changes between easy, medium, hard, and expert puzzles.
Frequently asked questions
› Should I write down candidates for easy puzzles? Trust & accuracy
Usually no — easy puzzles are solvable by scanning alone. Candidates help once you hit medium difficulty where pairs and triples come in.
› What if I get stuck on an easy puzzle? Troubleshooting
Almost always you missed a hidden single. Go digit-by-digit through every box and ask "where can this go?" — you will find the missed cell.
› How should I use this guide with a Kefiw tool? How-to
Use the guide as the plan and the linked Kefiw tool as the check. Read the steps first, try the move manually, then use the tool to compare outputs, catch edge cases, and decide whether the result actually fits your task.
› What mistake do tool guides help avoid? Troubleshooting
Tool guides help avoid using a utility mechanically without understanding what you are trying to accomplish. Most word, writing, and text utilities are fast, but speed can hide context mistakes. Know whether you are solving a puzzle, cleaning copy, drafting a line, or checking a rule.
› Can a tool guide help me learn the skill? How-to
A tool guide can help you learn if you pause before accepting the output and ask why it worked. Compare your first guess with the tool result, look for the rule or pattern, and repeat that review. Passive copying solves one task; active review builds the skill.