Logic · Illumination
Light Up
Light every room with bulbs — but no bulb may shine on another.
About Light Up
Light Up (Akari) is an illumination puzzle. Place bulbs in white cells so that every white cell is lit, while no two bulbs shine on each other. Numbered black cells tell you exactly how many bulbs touch them.
Play a new daily puzzle every day, or pick Easy, Medium or Hard in practice mode for unlimited puzzles.
How to play
- Place bulbs in white cells. A bulb lights its whole row and column until a black cell or the edge.
- Every white cell must be lit, but no two bulbs may light each other.
- A number on a black cell is how many bulbs touch it orthogonally; unnumbered black cells have no limit.
Satisfied numbers turn green, exceeded ones red. Unique solution.
Tap a white cell to cycle: bulb → “no bulb” mark → empty.
Tips & strategies
- A 4 on a black cell means bulbs on all four sides.
- A 0 means none of its neighbors can hold a bulb — mark them.
- A white cell that can only be lit from one place forces a bulb there.
FAQ
How do you play Light Up?
Place bulbs in white cells. A bulb lights its whole row and column until a black cell or the edge. Every white cell must be lit, but no two bulbs may light each other. A number on a black cell is how many bulbs touch it orthogonally; unnumbered black cells have no limit.
Is there a new Light Up puzzle every day?
Yes. A new daily puzzle arrives at midnight (your local time) and everyone gets the same one. Missed days can be played from the archive.
Do I need to sign up or install anything?
No. Daily Brain runs in your browser. You can add it to your home screen and it keeps working offline after the first visit. Progress is stored only on your device.
Are there difficulty levels and hints?
Practice mode offers Easy, Medium and Hard with unlimited new puzzles. Hints are available when you get stuck and are recorded in your result.