Plan the next move
Fifteen
Slide numbered tiles into order using one empty space.
THE OBJECTIVE
Think it through
Arrange the numbered tiles in reading order, with the empty square last. Use the empty space to move tiles without disturbing solved sections.
YOUR CONTROLS
Make your move
Click a tile in the same row or column as the gap, or use the arrow keys.
On a phone, use Touch: mark / reverse for a right-click action. Number puzzles include an on-screen number pad.
Choose an easier or harder grid in Type. Use Undo freely. Reveal solution shows the answer; it is a learning aid, not a hint. Use Finish & review to record practice time and actions. Complete 60 seconds of unrevealed practice with at least 3 board actions for the daily streak. Your last puzzle saves in this browser when device storage is available. Use Game → Download save file for a portable backup.
Puzzle engine by Simon Tatham and contributors · MIT licence · Full rules ↗