In OSRS, you change chat channels by using the chat tabs or by typing the channel shortcut before your message. The main ones are public chat, private/friends chat, clan chat, and guest clan chat.

Fast ways to switch

  • Public chat: type normally, or switch back with the public mode option in the chat box.
  • Clan chat: type // before your message to send it to clan chat.
  • Friends chat: type / before your message to send it to friends chat.
  • Guest clan chat: use the clan/community chat interface and join as a guest if the clan allows it.

Set a default channel

  • Right-click the All tab in your chat box and change your chat mode to the channel you want.
  • You can also click the Clan tab in the chat window to make clan chat your active channel.
  • Once set, you can type normally and your messages will go to that channel until you switch back.

Chat settings

  • Open Esc > Settings > Gameplay > Social > Chat Customisation to adjust chat display settings.
  • Clan and Friends Chat settings can also be found in the Community interface under Social.
  • If you only want to clear old messages, you can right-click the relevant chat tab and clear history.

Example

If you want to speak in clan chat without changing tabs every time, you can type //hello everyone and it will go to clan chat.

If you want, I can also give you the exact keybind/menu path for switching between public, clan, and friends chat on the current OSRS interface.