What is Yajilin?
Yajilin is a Japanese loop and shading logic puzzle. The grid contains arrow clues with numbers. Your job is to shade the right cells and draw one continuous loop through every remaining empty cell.
Each arrow clue tells you how many shaded cells appear in that arrow's direction. Clue cells are never part of the loop, shaded cells cannot touch orthogonally, and the finished loop cannot branch, cross itself, or leave loose ends.
- Follow each arrow clue to count shaded cells in that row or column.
- Do not shade two orthogonally adjacent cells.
- Draw a single closed loop through all unshaded, non-clue cells.
- The loop never passes through clue cells or shaded cells.
- The generator now prioritises varied, interesting loop shapes across every grid size, so some boards may have more than one valid solution.
How to play Yajilin online
Click or tap an empty cell to shade it. Click or tap between two neighbouring empty cells to draw a loop segment. A valid answer uses both parts of the puzzle: the arrow clues decide the shaded cells, and the unshaded cells must all belong to one loop.
Use Check when you want feedback without revealing the answer. Hint adds one useful shaded cell or loop segment from the generated solution, and Solution shows the complete board for study.
- Start with arrows that point along short lines.
- A clue showing 0 means every cell in that direction is unshaded.
- A clue whose number matches the available spaces can force shaded cells.
- Once a cell is shaded, keep its orthogonal neighbours unshaded.
- When the shaded cells are settled, the loop often has forced exits.
Yajilin grid sizes and difficulty
Smaller Yajilin grids are good for learning how arrows and shaded cells interact. Larger Yajilin boards create longer loops and more distant clue chains.
Easy puzzles use more direct clue pressure and fewer shaded cells. Medium puzzles give more space to reason. Hard Yajilin puzzles use bigger grids, more shaded cells, and longer consequences from a single arrow.
- 6x6 Yajilin is a friendly first size.
- 8x8 Yajilin gives a balanced logic challenge.
- 10x10 Yajilin creates longer loop deductions.
- Easy, medium and hard change the shaded-cell density and clue pressure.
- New puzzle builds another board for the selected size and difficulty.
Yajilin strategy tips
The best Yajilin strategy is to separate the puzzle into two questions. First, decide which cells must be shaded or unshaded from the arrow clues. Then use loop logic to connect every remaining empty cell.
Avoid guessing around the loop too early. A shaded cell removes a square from the loop, but it also forces neighbouring cells to stay open. Those open cells often become part of a narrow corridor with only one possible way through.
- Use 0 clues to mark safe loop cells.
- Compare two arrows that look down the same row or column.
- Watch for shaded cells that would touch another shaded cell.
- Do not close a small loop before every open cell is included.
- Cells with one line already usually need exactly one more exit.