About QuickBridge

I built QuickBridge because every existing option for cross-device file transfer either required an account, an app install, a shared Wi-Fi network, or a file upload to a server I did not control. None of those felt right for moving a file from my phone to my laptop in the same room.

The browser has had WebRTC since 2012. By 2022, it was mature enough in Chrome, Firefox, and Safari to support reliable large-file transfers over RTCDataChannel with backpressure management and stream-to-disk via the File System Access API. The hard part was not the P2P channel itself but the signaling: getting two browsers that have never met to negotiate a direct connection across NAT, quickly, without the user needing to understand any of that.

QuickBridge solves signaling with Supabase Realtime. The two browsers exchange SDP offers and ICE candidates over a shared Realtime channel for two to three seconds, then the signaling server drops out entirely. Everything after that is direct: encrypted, unchunked at the application layer, and never touching a QuickBridge server. Short Authentication Strings (SAS) derived from the DTLS fingerprints let both sides verify the connection is direct and not intercepted before any file data moves.

The QR code pairing flow took four or five iterations to get right. Early versions required both devices to be on the same page at the same time, which caused confusion when the QR expired or the guest refreshed. The current model generates a persistent 6-digit PIN that lives for the session and also embeds in the QR code, so a phone can join a session that started five minutes ago without either device reloading.

I am based in South Africa. QuickBridge is free and stays free. There are no ads and no plans for a paid tier. The source is on GitHub if you want to see how it works.