Sun & Moon Logic is a free online binary logic puzzle you can play instantly in your browser, no download, no account, and unlimited boards any time you like. Every board starts with a handful of pre-placed suns and moons plus a few = and × markers between certain neighboring cells, and your goal is to fill every remaining cell with a sun or a moon so that four rules hold everywhere at once: no three of the same symbol touch in a row or column, every row and every column ends with an equal split of suns and moons, and every = marker forces its two cells to match while every × marker forces them to differ. Tap a cell once to place a sun, tap again for a moon, and a third tap clears it back to empty — pre-placed clue cells can never be changed. Conflicting cells are outlined in red immediately, so you always know exactly where a placement breaks the rules. Play through 15 levels that grow the board from a gentle 4×4 up to a demanding 10×10 grandmaster grid, with fewer starting clues revealed at every step so later levels lean much more heavily on pure deduction. It is a free sun and moon puzzle unlimited, generated fresh for every level with no daily wait, no login, and no limit on how many boards you solve in one sitting.
How to play Sun & Moon Logic
- Some cells start pre-filled with a sun or a moon — these clues can never be changed. A few pairs of neighboring cells also show a small = or × marker.
- Tap any empty cell once to place a sun, tap again to change it to a moon, and tap a third time to clear it back to empty.
- No three of the same symbol may touch in a row or column — two in a row is fine, three is never allowed.
- When the board is finished, every row and every column must contain exactly the same number of suns as moons.
- An = marker between two cells means they must hold the same symbol; a × marker means they must hold opposite symbols.
- Any cells that break a rule are outlined in red right away. The board is solved the instant it is completely filled with no conflicts anywhere.
Tips
- Start from the = and × markers next to an already-known cell — they usually hand you a forced move immediately.
- Watch for two matching symbols sitting side by side: the cells on either end of that pair must be the opposite symbol, or you would create a run of three.
- Once a row or column already shows half its cells as one symbol, every remaining empty cell in that row or column must be the other symbol.
- On sparse, late-level boards, work outward from every clue at once rather than one at a time — chaining several small deductions together usually unlocks the next forced move.
FAQ
Is Sun & Moon Logic free to play?
Yes. It's a free binary logic puzzle in your browser with no download, no account, and no in-game purchases.
What are the rules?
Fill every cell with a sun or a moon so no three of the same symbol touch in a row or column, every row and column ends with an equal split of suns and moons, and every = or × marker between two cells is satisfied.
Is there a new puzzle every day?
No — boards are generated fresh for each level using a seeded layout, and you can replay any unlocked level as many times as you like instead of waiting for a daily reset.
Does Sun & Moon Logic work on mobile?
Yes — tap a cell to cycle it through sun, moon, and empty, so it plays the same on phones, tablets, and desktop with no download required.
How many levels does Sun & Moon Logic have?
There are 15 levels. The board grows from a 4×4 grid at Level 1 up to a 10×10 grandmaster grid at Level 15, with fewer starting clues revealed at each step along the way.
Is this the same as LinkedIn's Tango game?
It uses the same core rules as LinkedIn's Tango — balance suns and moons with no run of three, an equal split per row and column, and = / × markers between certain cells — built here as a standalone, generic binary logic puzzle rather than a LinkedIn product. Unlike LinkedIn's daily puzzle, there's no login and no once-a-day limit: replay any level as many times as you like.