ButterShare✓ Verified · buttershare.com

ButterShare is a browser-based peer-to-peer file transfer utility that allows users to send files directly between devices. By establishing a direct WebRTC connection, the tool streams data in real time without uploading files to intermediary cloud storage. The service does not require user registration, accounts, or app installations. It supports large transfers by utilizing the browser's Origin Private File System (OPFS) to write data directly to disk, and automatically falls back to an encrypted TURN relay if firewalls block a direct connection.