The previous record of 1.1 million online which was on March 22.
According to Steam Charts, 1,123 million users are currently playing CS:GO.
Such activity is associated with an in-game event - Shuttered Web.
March 30 is the last day of the operation, and gamers are trying to manage to get more rewards for completed tasks.
The Steam service in recent days also shows high online results - on March 29, 23.4 million players logged in to the service.