QuietdokuSudoku techniques
Every puzzle on Quietdoku can be solved by logic alone. These guides explain each technique step by step, from your first naked single to X-Wings and beyond, with an example board for each.
Naked single: the cell with only one possible digit
Learn the naked single, the first sudoku technique: find a cell where only one digit fits. Clear rules, a worked example and common mistakes.
Read →EasyHidden single: the only place a digit can go
A hidden single is a digit that fits in only one cell of a row, column or box. Learn how to scan for it, with a worked example and common mistakes.
Read →MediumPointing pairs and triples: when a box points along a line
Pointing pairs: when a digit in a box is confined to one row or column, remove it from the rest of that line. Rules, a worked example and pitfalls.
Read →MediumBox-line reduction: when a line claims a digit for one box
Box-line reduction: when a digit in a row or column fits only inside one box, remove it from the rest of that box. Clear logic and a worked example.
Read →HardNaked pair: two cells, two digits, fewer candidates
Learn the naked pair: two cells in a row, column or box with the same two candidates. See why it works, how to find it and a solved example.
Read →HardHidden pair: two digits with only two homes
A hidden pair is two digits that fit in only the same two cells of a unit. Learn how to spot it, what it removes and follow a solved example.
Read →HardNaked triple: three cells that lock three digits
A naked triple is three cells in one unit whose candidates use only three digits. Learn the rule, the tricky {2,5} {2,6} {5,6} case and an example.
Read →HardHidden triple: three digits squeezed into three cells
A hidden triple is three digits that fit only in the same three cells of a unit. Learn how to find it, what to remove and walk through an example.
Read →ExpertThe X-Wing: a rectangle that clears a column
Learn the X-Wing sudoku technique: what the pattern looks like, why it works, how to spot it, and a worked example with the exact candidates.
Read →ExpertThe Swordfish: an X-Wing with three lines
The Swordfish sudoku technique explained: the three-row pattern, why it works, how to scan for it, and a worked example with every candidate listed.
Read →ExpertThe XY-Wing: a pivot and two pincers
Learn the XY-Wing (Y-Wing) sudoku technique: a pivot and two pincers with two candidates each. Why it works, how to find it and a worked example.
Read →ExpertThe Skyscraper: an X-Wing with one corner shifted
The Skyscraper sudoku technique: two strong links on one digit, a shared base and two offset roofs. Why it works, how to spot it and a worked example.
Read →Quietdoku for iPhone and Android
Take the quiet with you.
The app works offline and adds the parts that make a habit stick.
- Four daily puzzles, one per level
- Streaks and collectible achievement cards
- Worldwide and country rankings, seasons
- Challenge a friend with a link
- Sign in with Apple or Google to keep progress across phones
Scan to download
Free · No ads · Optional Pro for unlimited practice