Zagreb is one of the 2,800 cities around the world included in Google Transit, which provides information on public and other types of transport, with detailed maps and directions on how to get to a destination.
The service is a result of ZET's cooperation with Google's Adriatic region office, reporters were told at city hall.
It is not yet possible to buy online a ticket for public transport in Zagreb, but this is being worked on.
Responding to a question from the press, spokesman Tomislav Juric said ZET transported between 700,000 and one million passengers daily.
Google Adriatic development manager Ivana Grbavac said negotiations were under way to include other transporters such as the rail in Google Transit.