Kosudoku: Multiplayer Sudoku

One Sudoku grid. You and a friend. Both solving it at the same time. 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 ON ONE BOARD • Up to 4 players on a single shared puzzle, live. • See opponents' attempts land in real time, colour-coded by player. • Claim a square by solving it first — it's yours, and it's gone for everyone else. • Wrong guesses cost you points, so speed alone won't win it. 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 Kosudoku is fully cross-platform — challenge any friend and compete in the same live matches, leagues and leaderboards, whatever device 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. Free to play and ad-free, with optional in-app purchases.