Popular Korean chat service KakaoTalk, which boasts 66 million users worldwide, has launched a new Group Call feature that lets up to five users participate in free HD Voice voice calls.

The company is billing the HD Voice support as a world’s first for group chats. Both Android and iPhone are supported, and the calls can be made over cellular connections. Kakao says data usage of a five-person group call will be the same as that of a one-on-one call, roughly 20Mb an hour.

kakaotalk groupcall 520x488 Korean chat app KakaoTalk adds support for HD Voice group calls for its 66m users

Group Call also includes KakaoTalk’s Talking Tom Cat and Talking Ben the dog voice filters, which is available in its Free Call service. Conversations will operate as chat rooms so that participants can exit and re-enter at will, as long as the room stays open.

Last week, KakaoTalk announced that it was taking its gaming service overseas. Kakao Games has already been a success within Korea, bringing revenue of $51.6 million. The company recently established ties with Yahoo Japan to make a push into Japan.

As messaging services are being bulked up with additional features, voice calls have been a popular addition. Research in Motion is working on adding voice calls to its BlackBerry Messenger service and Japan’s Line and China’s WeChat also already support the feature.

Image credit: PARK JI-HWAN / AFP / Getty Images