Fill One Line

A typical puzzle session starts slow. You look at the board, work out what the rules actually are, and make a tentative first move. Then the pattern clicks and the next few stages go quickly, until one stops you cold. That rhythm, easy then stuck then easy again, is the whole appeal. Most sessions last ten to twenty minutes before you reach a natural stopping point.

• Tap, hold and swipe on phones and tablets
• Mouse or trackpad on a computer; arrow keys or WASD where the game asks for movement
• Press Escape or the exit button to leave the full-screen player

1. 1Study the board before touching anything and find the pieces or tiles that have only one possible place.
2. 2Click or tap a piece to select it, then click where it should go; most puzzles let you undo a wrong move.
3. 3Clear the easy parts first so the remaining options narrow down on their own.
4. 4When you are stuck, step back and look for a rule you have not used yet rather than guessing.

• Free to play, nothing to install, no account needed
• Loads in the browser tab and opens full screen when you press Play
• Designed for a phone held upright
• Touch controls on phones and tablets, mouse and keyboard on a computer
• Listed under Puzzles

Fill One Line rewards patience more than reflexes. Nothing punishes you for taking a minute to think, and the moment a hard stage finally gives way is worth the wait. It runs free in your browser with no download, so it is easy to pick up for a short break and leave again.

People who like to think rather than react, anyone killing time on a commute, and players who want something quiet to do with one hand on a phone. Younger children may need help with the trickier stages.

Does Fill One Line save my progress?

The game may store progress in your browser, so returning on the same device and browser usually picks up where you left off. There is no account, so progress does not carry across devices.

Is there a time limit?

Puzzle games on this site vary. Many let you think as long as you like, while some add a timer for extra score. Nothing stops you from replaying a stage.

Can I play on my phone?

Yes. Most puzzles here are built with touch in mind, and tapping a piece works the same as clicking it. Rotate to landscape if the board looks cramped.