Create a group: Messages → New chat → New group → choose members → group name (up to 40 characters) → Create group. You become the admin.
Limit: 100 members.
Who is added directly and who gets an invitation? It depends on each person's setting: More → Privacy → Who can add me to groups:
- My people (default): your friends, and people who have your number saved while you have theirs.
- Everyone.
- Nobody — always ask me.
Anyone whose setting doesn't allow you to add them gets an invitation they can accept or decline, and they can't see messages before accepting.
Admins can: change the name and photo, use an invite link (anyone who opens it joins directly — share it only with people you trust; "New link" stops the old one), add members, make admins and remove members.
Everyone can: see photos and videos, mute notifications, set disappearing messages, Report group, and Leave group (past messages stay on your phone).
If the last admin leaves, the longest-standing member becomes admin.
Not available yet: group calls.