On the same Wi-Fi, devices with share open appear by themselves. A VPN, Private Relay, or IPv6 on only one of them can hide them from each other; then open the link, or scan the code, on the other device. The link works from any network. It stops working when this page closes, when you take a new link, or half a minute after a connection drops.

The receiver chooses what to accept. Keep both tabs open until the transfer finishes. Received files are saved to this browser's storage as they arrive, so a transfer can be as large as the space it allows; in a private window, or a browser without that storage, they are held in memory, up to 256 MB at a time. Remove received files to free space.

Files travel over an encrypted WebRTC connection and stay out of this site's server storage. The server only introduces the two devices and passes the connection details. A relay may carry encrypted data when configured.