Play Expert Sudoku Online - Free
Expert Sudoku is where the classic advanced patterns live: X-Wing, Swordfish and XY-Wing. Givens are sparse, candidates stay ambiguous deep into the solve, and progress comes from spotting structures that span the whole grid rather than a single box. Every puzzle here is still strictly logical - verified to have exactly one solution - so a stuck position always has a findable next step. Bring full notes.
Techniques you'll need
- X-WingWhen two lines lock a candidate into the same two crossings.
- SwordfishWhen three lines lock a candidate into the same three crossings.
- XY-WingWhen one pivot and two wings remove a shared candidate.