Unlisted, not secret
Rooms are never listed. They do not appear on the homepage, there is no directory, no search box and no way to browse what exists, so nobody stumbles into yours. What protects the room is that nobody knows the address. That makes it private in the practical sense that matters most of the time, and it is worth being clear that it is not the same thing as encrypted or password protected. Anybody holding the link can walk in.
Pick a name nobody would guess
This follows directly from the point above: the address is the key, so the strength of the room is the strength of the name. A single common word offers nothing. Two or three unrelated words joined with hyphens is enough to make guessing hopeless, and it stays easy for your group to read in a message. Treat the finished link the way you would treat any other link you would not want forwarded.
What gets stored, and for how long
A room keeps the last fifty messages and nothing before them. Once a day passes with nobody in it, the room resets and everything in it is gone. You can also switch on a timer so messages delete themselves after a chosen period while people are still talking. There is no archive to request, no export to download and no search across old conversations, because none of those exist.
Messages between two people
Tapping somebody's name opens a private conversation with just them, running alongside the room. Those messages are handed straight from one browser to the other and are never written to the server, which is a stronger guarantee than the room itself gives. It also means they cannot be recovered afterwards by anyone at all, so treat them as spoken rather than written.
Where the privacy stops
Three honest limits. Anybody with the link can open the room, including somebody the link was forwarded to. The connection is encrypted, so the contents are not readable in transit, but a network administrator can still see that the domain was visited. And there is no human moderation team watching, so a room that gets shared further than you intended is something you handle yourself, with the moderator tools and the fact that the whole thing wipes itself within a day.
Questions people ask
Can I put a password on a room?
No. The link is the only key. A long unguessable name achieves roughly the same thing in practice, but if you need real access control this is not the right tool.
Can somebody find my room by searching?
No. Rooms are not listed anywhere on the site and the chat pages are not indexed by search engines, so a room cannot turn up in search results.
Is the chat encrypted?
The connection is encrypted in transit, in the same way as any site on HTTPS. It is not end to end encrypted, so this is the wrong choice for anything that genuinely needs that.
What if the wrong person joins?
Whoever opened the room can remove and ban them, and anybody can ignore them with one tap. If the link has spread further than you want, the fastest fix is to open a new room with a different name and send that link instead.
Does anything remain after we are done?
No. Once the room has been quiet for a day it clears itself completely, and the private one-to-one messages were never stored in the first place.