Even here no puzzle needs a guess: each one was solved step by step by the same hint engine before it reached you.
New at this level
- X-Wing — In two lines the digit sits on the same two columns → erase it from the rest of those columns
- Y-Wing (XY-Wing) — Three two-candidate cells form a loop → erase from any cell that sees both wings
- Simple Colouring — Paint the digit's either-or chain in two colours → erase the side that contradicts itself
- Swordfish — In three lines the digit's places fall inside the same three columns → erase it from the rest of those columns
All levels
- Easy · naked singles only
- Medium · up to hidden singles
- Hard · up to pairs
- Very hard · up to intersections and triples
- Expert · up to advanced techniques
- How sudoku difficulty is graded