Free logic puzzles to play and print

Hard Logic Puzzles

Large logic grids with few clues. Expert puzzles need trial and contradiction; every puzzle still has a single answer.

Hard logic puzzles are grid puzzles where you match people to items using only written clues, and this page makes new ones for you to solve in your browser. It is free, needs no sign-up, and nothing needs to be installed. Each puzzle is made on your device, so nothing is uploaded. The page opens on a 5x5 Hard puzzle: five categories with five items each, such as friends, pets, ages and drinks. You can switch to 4x5 or 5x6, and to the Expert level for the hardest logic problems. Every puzzle has exactly one solution, so you never have to guess which answer the clues intend. It is a good difficult logic puzzle for adults, and you can print the puzzles with or without answers.

How to use the Hard Logic Puzzles tool

  1. Choose a size and level. The page opens on 5x5 Hard. Pick 4x5, 5x5 or 5x6, and Hard or Expert.
  2. Read the clues. Tap a clue to cross it out once you have used it.
  3. Mark a cell by tapping it once for ✗ (no) or twice for ● (yes). Right-click or press and hold to place ● directly.
  4. If you use a keyboard, the arrow keys move between cells, X or Space puts ✗, O or Enter puts ●, and Backspace clears a cell.
  5. Leave Auto-cross on. When you place ●, the rest of its row and column in that block are crossed out, because each item pairs with only one item.
  6. Turn on Show mistakes to see impossible combinations in red, such as two ● marks in one row.
  7. When you are stuck, press Hint. It marks one cell and names the clue and the reasoning behind it.
  8. Press Check to count wrong marks without seeing which.
  9. Use Undo, Redo or Reset to fix a mistake. Show solution reveals the answer.

A timer runs while you play and pauses when the page is hidden. When you finish, a message shows your time and how many hints you used. Copy link shares the exact puzzle, and New puzzle makes a different one with the same settings. On the Print tab, you can print one puzzle per page for 4x5 and larger, on Letter or A4, with answer pages on or off and a Name and date line.

What makes a logic puzzle hard?

A logic grid puzzle is hard when its clues need more than direct facts and simple cross-checking. Hard clues include pair clues, exact differences, positional clues and “all different” clues.

A logic grid puzzle (also called an Einstein puzzle, zebra puzzle or deduction puzzle) has categories with the same number of items each. The first category is always the people, and the hidden answer pairs every item with exactly one item from every other category. The clues are the only information you get.

The tool measures difficulty by the weakest set of solving rules that solves the finished puzzle. Hard puzzles can be solved without guessing. They use pair clues (“Of A and B, one owns the cat and the other owns the dog”), exact differences (“is 2 years older than”), directly-left-of and next-to clues, and “all different” clues. Hard puzzles for 5x5 often have only 11 to 13 clues. Expert puzzles have the fewest clues and need at least one trial step.

How do you solve hard logic puzzles?

Hard puzzles fall to careful chains of reasoning; Expert puzzles also need trial and contradiction: assume a cell is ●, follow everything that assumption forces, and if you reach a contradiction, that cell must be ✗.

Start with the ordered categories, such as ages or finishing places. Write down which item sits at each end, because many comparison clues depend on it. Next, turn each pair clue into two either/or facts. Then, after every new ● mark, re-read every comparison clue, since one new fact often unlocks several others. On an Expert puzzle, when you are stuck, find a cell that has only two possible options and test one of them. Follow the consequences in your head or on paper. If a row or column ends up with no possible item, the test was wrong, and the other option is the answer.

Are these puzzles guaranteed to have one answer?

Yes. Every puzzle the tool makes has exactly one solution. The generator runs a complete solver and proves this before it shows you the puzzle. If the clues leave two possible answers, that puzzle is not shown. You can rely on the clues to lead to a single grid, so you never need to guess between two answers.

Frequently asked questions

Is it free, and do I need an account?

Yes. It runs in your web browser, is free, and needs no sign-up. There is nothing to install, and your puzzles are made on your device without being uploaded.

Does it work on a phone or tablet?

It runs in the browser, so you open the page rather than installing an app. Marking works with a tap for ✗ and two taps for ●, or a press and hold for ●. The keyboard shortcuts are useful when you use a computer.

How long does a hard logic puzzle take?

It depends on the solver. A 5x5 Hard grid usually has 11 to 13 clues and needs several chains of reasoning; the timer on the page shows how long you took, and the finish message also counts the hints you used.

Will I lose my progress if I reload the page?

No. Your marks are saved in your browser for each puzzle, so a reload does not clear them. Undo, Redo and Reset still work as usual.

Can I print hard logic puzzles with answers?

Yes. On the Print tab, choose one puzzle per page for 4x5 and larger, on Letter or A4 paper. You can turn answer pages on or off and add a Name and date line. You can print 1 to 10 pages. On 5x6 puzzles, the empty answer table is left off so the grid stays large enough to write in.