CoSudoku vs SharedSudoku

Think you’re the fastest solver on the grid? It’s time to prove it. Cosudoku takes the classic brain-training experience you love and transforms it into a high-stakes, real-time battle of logic and speed. No more slow-paced solo play—just pure, head-to-head competition. We built Cosudoku for the players who live to win. We’ve created a seamless, low-latency arena where you can outsmart and outpace your rivals in every match.

Shared Sudoku brings the classic number puzzle to life with three ways to play: solo, competitive, and cooperative. SOLO MODE Sharpen your skills with classic Sudoku. Choose from three difficulty levels — easy, medium, or hard — and track your progress with detailed statistics including best times, win streaks, and game history. COMPETITIVE MODE Race head-to-head against another player! Both players receive the same puzzle and compete to solve it first. Connect instantly online — no accounts or internet required. COOPERATIVE MODE Work together on a shared board. See your partner's moves in real time as you collaborate to complete the puzzle. Each player's contributions are color-coded so you can see who placed what. FEATURES • Three difficulty levels with unique puzzle generation • Pencil marks for noting candidates • Undo and redo support • Mistake tracking • Number highlighting — long press any number to highlight all instances on the board • Game statistics: best times, win rates, current and best streaks, game history • Online multiplayer — play with anyone, anywhere • Clean, modern interface with haptic feedback Shared Sudoku is completely free with no ads, no in-app purchases, and no data collection.