Filling Puzzle Online

Filling is one of the classic one-player logic games in Simon Tatham's Portable Puzzle Collection. Mark every square with the area of its containing region.

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Preparing the game board and controls.

Game Objective

Write a number in every blank square. Same numbers that touch horizontally or vertically form a region, and the number of squares in that region must match the number: 1 stands alone, 2 makes a pair, 3 makes a group of three, and so on.

Mark every square with the area of its containing region.

How to Play

Click a square, then type the number you want to place there. Drag to select several squares and type once to fill all of them. Select one or more squares and press Backspace, Space, 0, or Enter to clear them.

These puzzles reward careful deduction more than speed. Start with the most constrained clues, eliminate impossible choices step by step, and avoid guessing unless the puzzle specifically calls for it.

Beginner Tips

  • Start with 1s and small numbers near walls or corners, because their possible shapes are easiest to see.
  • A group of 4 must contain exactly four connected 4s. It cannot touch another 4, or the region would become too large.
  • If a blank square can only join one nearby region without making its square count wrong, that number is forced.

Official Rules

For the full original rules, examples, and advanced options, read Simon Tatham's official manual.

Read the official manual

Frequently Asked Questions