Logic Grid Puzzle Solver
The classic elimination grid for logic puzzles, made interactive. Set up your puzzle’s categories, click cells to record what each clue tells you — ✕ for impossible, ✓ for confirmed — and the grid handles the bookkeeping: automatic cross-outs, deductions that chain across categories, and instant contradiction alerts with undo.
Click a cell to cycle: blank → ✕ → ✓ → blank. Bold marks are yours; faded marks were deduced automatically.
| Cat | Dog | Fish | Parrot | |
|---|---|---|---|---|
| Alice | ||||
| Ben | ||||
| Carla | ||||
| Diego |
| Red | Blue | Green | Yellow |
|---|---|---|---|
| Cat | Dog | Fish | Parrot | |
|---|---|---|---|---|
| Red | ||||
| Blue | ||||
| Green | ||||
| Yellow |
What Is a Logic Grid Puzzle?
A logic grid puzzle (logic problem, Einstein riddle, zebra puzzle) presents several categories — names, pets, colors, jobs — where each item pairs with exactly one item from every other category, and a set of written clues that pin the matching down. The triangular grid of pair tables is the standard solving tool: each small table tracks one pair of categories, and every clue becomes an ✕ (that pairing is impossible) or a ✓ (that pairing is certain). Fill enough marks and the whole solution falls out by elimination.
How to Solve Logic Grid Puzzles
- Translate every clue into marks. “Ben doesn’t own the dog” is one ✕. “The fish owner wears green” is a ✓ in the pet/color table. Do a full pass over all clues before thinking hard.
- Chase the forced cells.When a row has all but one cell crossed out, the survivor is a ✓ — this grid confirms it for you automatically.
- Chain across categories. If Alice owns the cat, and the cat owner drinks tea, then Alice drinks tea. The grid applies these transitive deductions the moment both links exist.
- Re-read clues with new eyes.Relative clues (“the tea drinker is older than the dog owner”) yield new ✕ marks each time something gets confirmed. Cycle through the clue list until the grid completes.
- Trust the red cells. A contradiction means one of your marks misreads a clue — undo and recheck rather than pushing on.
Worked Mini Example
Three friends (Alice, Ben, Carla), three pets (cat, dog, fish). Clues: (1) Alice is allergic to fur, (2) Ben’s pet barks.
- Clue 2 is a direct hit: ✓ Ben–dog. The grid instantly crosses out dog for Alice and Carla, and the other pets for Ben.
- Clue 1 rules out both furry pets for Alice: ✕ Alice–cat. With dog already crossed out, her row has one cell left — the grid confirms ✓ Alice–fish.
- That leaves a single open cell in Carla’s row: ✓ Carla–cat. Solved with two clicks.
Real puzzles are the same loop at a larger scale — the grid just saves you from the clerical errors that sink paper solves.
Frequently Asked Questions
What is a logic grid puzzle?
A deduction puzzle where items across several categories pair one-to-one, and written clues let you eliminate your way to the unique matching. Also known as logic problems, Einstein riddles, or zebra puzzles.
How does the interactive grid help me solve?
Click cells to cycle blank, ✕, ✓. Each ✓ crosses out its row and column automatically, near-complete rows are finished for you, and confirmed links chain across categories — so the bookkeeping is always correct.
What deductions happen automatically?
Row/column elimination from every ✓, last-cell-standing confirmations, and transitive logic: A=B with B=C gives A=C, and A=B with B≠C gives A≠C, applied repeatedly until nothing new follows.
What happens if I make a contradictory mark?
The conflicting cells turn red and a warning appears. Undo steps back one mark at a time — derived marks vanish with the mark that caused them.
Can I use my own puzzle’s categories?
Yes — 2 to 4 categories with 3 to 5 items each, all names editable. Reset marks keeps your setup; Clear all restores the example.
Does it read the clues and solve by itself?
No — you interpret the clues (that’s the puzzle), the grid guarantees the consequences. Every deduction you’ve earned appears instantly and correctly.
Is it free?
Yes, free with no signup. Everything runs in your browser and your puzzle never leaves your device.
Related free tools
Every free PuzzlePage tool
All free, no signup, and they run in your browser.
Word Solvers & Finders
Daily Game Solvers & Helpers
Logic Puzzle Solvers
Cipher Tools & Decoders
Translators & Converters
Word Lists & Dictionary