The rules
- Every puzzle here is solvable by reasoning alone. You never have to guess.
- Got it
- Fill every cell with one of two symbols, following three simple rules.
- Every cell ends up light or dark. None stays empty.
- No three cells in a row or column may share the same symbol.
- Every row and every column holds an equal number of light and dark cells.
- No two rows may be identical, and no two columns may be identical.
- Tap a cell to make it light, tap again to clear it. Long-press to mark it dark. Drag across several cells to paint the same symbol on all of them.
- Every rule break is marked the moment it happens. A board with no warnings on it can still be unfinished — check that no cell was left empty.
How to play here
Three ways to play
Campaign
Chapters that start gently and bring in one new idea at a time.
Daily puzzle
A new board every day, the same for everyone. Solve every one in a month and that month's trophy is yours.
Endless
Keep going as long as you like, in Easy, Medium, Hard and Expert.
Common questions
Is Bini free?
Yes. You can play here without paying and without an account. Ads keep the lights on.
Where is my progress saved?
In this browser, on this device. If you clear the site data, your progress goes with it. A free Solvarium account keeps it safe.
Does it work on a phone or tablet?
Yes. It runs in any current browser on phones, tablets and computers, and the board resizes to fit the screen.
Does every puzzle really have one solution?
Yes. Every board goes through a solver before it ships, and anything with more than one solution is thrown out.