what kind of online chats are you looking for (and by that, I mean) are you looking for mental health advice about a certain condition?. are you looking for a place to vent but not necessarily get a response?. are you looking for a general mental health chat where anything is discussed.

I am aware of healthful chat, which is a website that contains chatrooms for various conditions (anxiety, bipolar, eating disorders), and it also has a lounge.

7 cups of tea also has a chatroom and a facility to chat 1 on 1 with a free listener. some of the listeners are really good