Can you see my files or their names?+
No. Each file and its filename are encrypted with AES-256-GCM in your browser using a key derived from the room password (PBKDF2, 250,000 iterations). The server only stores ciphertext and the encrypted size, and never receives the password.
Can someone who guesses my room name get the files?+
Not without the password. Listing, downloading and deleting a room's files all require a proof derived from the password, so a room name on its own returns nothing but the salt. Even if the ciphertext leaked, it can't be decrypted without the password.
How big can files be, and how many?+
Up to 4 MB per file and 10 files per room (25 MB total). Everything is held only in server memory, so the limits keep it small and short-lived.
How long do files stay up?+
You pick 5 minutes, 30 minutes, 1 hour or 6 hours. Every new upload resets the room's timer to that duration. When it expires the room and every file in it are wiped; you can also delete single files or the whole room at any time.