Sudoku helper

Candidate and Pattern Spotter

Enter a puzzle, fill all legal candidates, then highlight common basic solving patterns.

Tap a digit, then a cell: Fill places the value; Pencil toggles that candidate; Color marks the cell.

Pattern Hints

Advanced Pattern Hint

Availability

Quick Spotting Tips

W-Wing
[XY]: two identical [XY] cells linked by a strong X pair.
XY-Wing
[XY]: pivot [XY] with wings [XZ] and [YZ].
XY-Chain
[XY]: chain bivalue cells with alternating links.
XYZ-Wing
[XY]: pivot [XYZ] with wings [XZ] and [YZ].
2-String Kite
[X]: perpendicular lines with two X cells each, meeting in one box.
Skyscraper
[X]: parallel lines with two X cells each, aligned on one end.
Finned Swordfish
[X]: 3 x 3 except 1 fin in the removal box.

Board Actions

0 filled cells

Built-in puzzles

From text box

Spot / Filter

Basic spots only
Advanced Spot / Filter

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Choose a spot/filter button to highlight matching cells.