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The Fill

Each puzzle is a grid of blocks you must cover with one continuous swipe, without lifting your finger or mouse and without backtracking. If you get stuck, a free hint reveals part of the route. Later puzzles grow harder as you progress, and it plays in portrait orientation on desktop, phone, or tablet, with no installation needed.

The Fill — play free online

About this game

Sharpen your mind with a connect-the-block-style one-line brain training puzzle game.
A simple but addictive one-line puzzle game that’s completely free to play.

Your brain becomes more active the more you play.
During your commute, before you sleep… enjoy downtime with brain training.

The rules are extremely simple.
Just fill in all of the blocks using only one line.

Use hints for puzzles that are too hard to solve.
Hints are also free, of course.

How to play

Swipe or draw one continuous line that passes through every block without lifting your finger or mouse.
You must fill every block in one go; backtracking isn’t allowed.
If a puzzle feels too complex, tap the hint icon to reveal part of the solution and it’s free.
s you complete puzzles, higher difficulty levels unlock more challenging puzzles.

Questions people ask

Can I play The Fill online for free?
Yes. Open The Fill in this browser and press Play. There is no download or account required.
Do I need to install The Fill?
No. The game runs inside the browser page, so there is nothing to install.
Does The Fill work on mobile?
This game does not list touch controls. For the best experience, use a keyboard and mouse.