: Agar.io is a free H5 game for kids to play online at GaheGames.com. You can play Agar.io in your browser for free. Play online with players around the world as you try to become the biggest cell of them all! Control your tiny cell and eat other players to grow larger! But watch out that players bigger than you will be trying to make you their lunch. Survive and eat long enough to become the biggest cell in the game!