Arrow Loop Solver

Arrow Loop Solver — Step by Step

Click a square to make it a clue, press an arrow key and type its number, then press Solve. Or play a generated puzzle and send it here with one click.

Arrow Loop Solver: rules, how to use it, tips

Shade some squares and draw one loop through all the others, so that arrows count the shaded squares in their direction and shaded squares never touch.

The rules

Every square that isn’t a clue is either shaded or on the loop.
The loop is a single closed path through square centres, moving across or down, never crossing or branching.
Shaded squares never share a side.
An arrow’s number is the count of shaded squares in that direction, all the way to the edge of the grid.

Using the solver

Choose the size and enter the arrow clues (or press Sample).
Press Solve and step through: arrow counts, no touching, two joins per square and the one-loop rule.

Tips

Zeros first. A 0 arrow means every square that way is on the loop.
Corners. A corner square on the loop has only one way to turn — and a square boxed in by shaded squares and clues can’t be on the loop, so it’s shaded.
No touching. Next to a shaded square every square is on the loop (or a clue).
Dead ends. A loop square with only two open sides uses both of them.

The full guide, with a worked example and common mistakes: How to play Arrow Loop.

Questions

Do clue squares block the arrow’s count?

No — the count runs all the way to the edge; clue squares along the way are simply skipped.

Can the loop pass through a clue?

No — clue squares are neither shaded nor on the loop.

Is there always one answer?

Yes — every puzzle here is checked to have exactly one solution.

How do I solve one from a book?

Open the Arrow Loop Solver, enter the clues and press Solve.