NO ADS. Not a banner, not a video, not one that appears "just this once" between games. Kosudoku has never shown an advertisement and never will.
Kosudoku is Sudoku as a live race. You and your opponent get the identical board and fill it simultaneously — their guesses appear on your screen the moment they make them. Every square belongs to whoever solves it first. Hesitate on a cell you'd worked out, and you'll watch it turn their colour.
That's the whole game: a shared grid, a running scoreboard, and the pressure of knowing someone else is looking at the same empty square you are. Add a friend, build a head-to-head record, and settle it again tomorrow.
Race head-to-head
- You and one friend on a single shared puzzle, live.
- See every guess they make, the moment they make it.
- Claim a square by solving it first — it's yours, and it's gone.
- Wrong guesses cost you points, so speed alone won't win it.
- Track your head-to-head record against each friend you play.
- Up to 4 players when you can get a group together.
Build a streak, hunt the bonus cells
- Chain correct answers to raise your streak multiplier.
- Gold cells double your points. Rainbow cells triple them.
- Land a streak on a bonus cell and the score jumps.
Play solo any time
- Four difficulties, from Easy to Expert.
- Chase your own best times and scores.
- Every solo game still feeds your league points and rank.
Climb the leagues
- Weekly league groups of up to 20 players.
- Finish top three to promote — slip and you drop.
- Ranks run Bronze through Grandmaster.
Put something on it
- Wager Quickets on a match. Everyone matches the stake, winner takes the pool.
- Earn Quickets from wins, streaks and daily rewards.
- Spend them in the store on board skins, themes, fonts and player colours.
Play with friends
- Add friends, see who's online, challenge them directly.
- Schedule a match for later and get a reminder when it's time.
- Chat in the lobby and mid-game.
Cross-platform. iPhone and Android players compete together in the same live matches, leagues and leaderboards. Challenge any friend, whatever they play on.
No ads, ever. Kosudoku is completely ad-free. No banners, no interstitials, no rewarded videos, no "watch an ad to continue". Your board is never interrupted.