Leaving is quieter than you might expect
Regular group members aren't sent a push notification when you leave, though a small system note appears in the group's chat history for anyone who scrolls back to that point. Group admins, however, do get notified.
Your own chat history is not deleted automatically
Leaving only removes your membership β it doesn't erase your existing copy of the conversation. If you want the history gone too, you need to delete the chat separately from your own chat list.
Frequently Asked Questions
Will everyone in the group see that I left?
A system message noting that you left is added to the group's history, visible to anyone who scrolls back to that point, though ordinary members aren't pushed a notification about it β only admins are notified directly.
Can I rejoin a group after leaving?
Only if someone still in the group, typically an admin, adds you back. Leaving doesn't leave you any way to rejoin on your own.