Advanced fish

X-Wing Sudoku Strategy: Lock Rows and Columns to Clear the Board

X-Wing removes a digit from entire columns or rows when two lines share the same two candidate positions. It’s the tactic that separates confident intermediate players from advanced solvers. Use this breakdown with the Pure Sudoku interface to visualize every wing before committing moves.

2×2 Rows or columns form the X shape
4 cells Only positions that keep the digit alive
8+ cuts Average candidates removed when the pattern triggers

How to find an X-Wing

  1. Choose a digit and scan every row for units where it appears exactly twice.
  2. When two rows share the same column positions for that digit, lock them in—those are the wing corners.
  3. Eliminate the digit from the rest of those columns (or flip rows/columns depending on how you spot it).
  4. Recalculate notes; singles and pointing moves usually appear immediately.

Interactive play-by-play

See the X-Wing rectangle fire

The animation locks two rows into a tidy rectangle and erases every other copy of the digit.

Step 1

Match the lines

Rows 2 and 4 each have the digit 3 in the same two columns. That forms the corners of the X-Wing.

Step 2

Clear the shared columns

Every other 3 in those columns vanishes. Only the four corners remain possible.

Step 3

Use the cleaned columns to place digits

Once other candidates disappear, each column often collapses into a single spot and you can fill both 3s.

Step 1 of 3

Practice plan

Day 1–2: Play an advanced board and highlight one digit at a time until you find at least one X-Wing.

Day 3: Switch to the solver tool and load finished puzzles. Remove a few givens and reconstruct the X-Wing manually.

Day 4: Join a multiplayer match and race to be the first player to call out the wing you used.

Where to go next

Play Sudoku Online Download on the App Store