Kosudoku: Multiplayer Sudoku

About this app

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.

RANKING OVERHAUL Rank points now scale with the size of the match. Beat three opponents and you gain three times what you'd gain from beating one, while a loss always costs the same. No lobby size is worth farming any more. REBALANCED TIERS Bronze through Grandmaster now sit at thresholds you can actually reach, and your rank can no longer drop below zero. STILL NO ADS Kosudoku has never shown an advertisement and never will. No banners, no interstitials, no rewarded videos. Plus stability fixes and polish throughout.

Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.

1. First observed Sep 14, 2026 · 5:23 PM Free