Fifteen Puzzle
By Arnis Ritins · MIT license. Source · All credits
About Fifteen Puzzle
Fifteen Puzzle is the classic sliding-tile game. Slide the numbered tiles around the one empty space until they line up in order from 1 to 15. Simple to learn, and oddly hard to put down.
How to play
Tap a tile next to the empty space to slide it in.
Rules of Fifteen Puzzle
- Fifteen numbered tiles sit in a 4x4 frame, leaving one empty square.
- A tile can only move into the empty square, and only from directly beside it. Tapping a tile in the same row or column as the gap slides the whole line.
- The goal is the numbers in order, one to fifteen, reading left to right and top to bottom, with the gap at the end.
- Solve it in rows. Finish the top row completely, then the second, and never disturb a finished row again.
- The last two rows have to be solved together as columns rather than row by row.
- Exactly half of all possible scrambles are solvable, so a legitimate shuffle will always have an answer.
- Every shuffle is solvable. The board is scrambled by making a hundred random legal slides from the finished position rather than by dropping the tiles in at random, so there is always a way back and you are never handed an impossible board.
Controls
- Tap a tile next to the gap to slide it
What makes it worth playing
- Slide the numbers back into order
- A scramble button for a fresh puzzle
- A solver if you want to see it done
- Small enough to finish in a break
Screenshots
Captured from this build on 2026-08-26.
Tips from playing it
- Solve the top row first, then the left column, and never disturb them again.
- The last two tiles of a row need a rotation, not a straight slide.
- Work down to a two by two square at the end. That part solves itself.
Why this game is here, and what we changed
Chosen because it is genuinely good and its licence (MIT) allows us to host and modify it, which we verified in the project's own files. We host it on our own servers, so it loads straight into the game with no third-party ad code and no pre-roll video. It arrived using a gameplay screenshot as its icon, which looks poor at tile size, so we drew it a proper one. We played it through on a real phone-sized screen on 2026-08-26 before publishing this page, and the screenshots above are from that session rather than from the original project.
More on how we pick and fix these: what we changed in the open-source games and how we test a game.
- Category
- Puzzle
- Plays in
- Your browser, no download
- Orientation
- Landscape
- Players
- One player.
- Difficulty
- Fiddly the first time, routine once the method clicks
- Typical session
- 3 to 8 minutes a puzzle
- Last tested by us
- 2026-08-26
- Created by
- Arnis Ritins (MIT)
