How FileTransferFree works
FileTransferFree is a web app that uses your browser’s built-in WebRTC stack to move files directly between two devices. Nothing about your files is uploaded, stored, scanned, or logged on our infrastructure. Below is a complete walk-through of what happens when you press Connect and drop a file onto the page.
1. Each browser becomes a peer
When you open FileTransferFree, the page generates a short, human-friendly room code (six characters, easy to read aloud) and registers itself with a public WebRTC signaling broker. The signaling broker’s only job is to help two browsers exchange the small messages they need to discover one another — it does not see any of your files.
2. The two devices exchange a handshake
When the second device enters your code (or scans the QR), the broker forwards a few messages so the two browsers can negotiate a direct connection. This is called the SDP / ICE handshake. After the handshake, the two devices establish a peer-to-peer RTCDataChannel — an encrypted, ordered, reliable transport between them.
3. Files stream in 64 KB chunks
When you drop a file, FileTransferFree sends a small description first (filename, size, MIME type), then streams the file in 64 KB binary chunks over the data channel. The receiver reassembles the chunks into a complete file and offers a one-click Save button.
4. End-to-end encryption
WebRTC data channels are mandatorily encrypted with DTLS. Even if a chunk were intercepted on the network, it would be unreadable. Because the only thing the signaling broker ever sees is the handshake metadata, the broker cannot eavesdrop either.
What the page never does
- It never uploads your files to FileTransferFree or to any cloud bucket.
- It never asks you to create an account.
- It never plants tracking cookies (we use no analytics by default).
- It never imposes a file-size limit — your link speed is the only ceiling.
- It never stores your IP address or any personally identifiable information.
Is it really secure?
Yes. WebRTC mandates DTLS 1.2+ encryption on every data channel — it cannot be disabled. Even if traffic were intercepted between the two devices, the content would be completely unreadable. Because no file bytes ever pass through our servers, there is nothing for us to lose, leak, or misuse.
How fast is it?
On a typical home broadband connection, you can expect 5–25 MB/s. On the same local Wi-Fi network, transfers regularly reach 50–100 MB/s. The speed is limited only by the slower of the two devices’ upload/download bandwidth — FileTransferFree itself adds no artificial cap.
Privacy by design
Because the file bytes never touch our servers, there is nothing for us to log, leak, or hand over. The only metadata we briefly see is the random room code your two browsers use to find each other — and that is discarded the moment the connection closes. See the privacy policy for the full breakdown.