A logic grid puzzle (also known as a logic problem or Einstein puzzle) is a type of deductive reasoning puzzle where you use a grid to match items across different categories based on a set of clues. The goal is to find the unique solution that satisfies all given constraints by systematically eliminating impossibilities and confirming matches.

Click on any cell to cycle through states: Empty → ✓ (Match) → ✗ (No Match) → Empty. Mark ✓ when you've confirmed two items belong together, and ✗ when you've ruled out a connection. Use the clues to make deductions — when you find a match in one subgrid, you can often deduce non-matches in related subgrids through transitive reasoning.

Easy (3×3): 3 categories with 3 items each — 3 subgrids, straightforward clues with many direct matches.
Medium (4×4): 4 categories with 4 items each — 6 subgrids, moderate clues requiring multi-step reasoning.
Hard (5×5): 5 categories with 5 items each — 10 subgrids, challenging clues that require complex deductive chains and cross-referencing.

• Start with the most direct clues — they give you immediate ✓ marks.
• When you mark a ✓, immediately mark ✗ for all other cells in that row and column within the same subgrid.
• Use transitive deduction: if A=B and B=C, then A=C.
• Re-read clues after each deduction — new information often unlocks previously unusable clues.
• Work on one subgrid at a time but keep an eye on cross-relationships.

Yes! Every puzzle generated by this tool is verified to have exactly one valid solution that satisfies all clues. The generator creates a random solution first, then derives clues from it, ensuring consistency and uniqueness. If you're stuck, use the Hint button to reveal a helpful match.