ZetaShare Building private file transfer with WebRTC
masterdegrees Sunday, November 23, 2025I built ZetaShare because I wanted a file transfer service that doesn’t spy on me — no tracking, no data collection. The project was inspired by ToffeeShare, but after seeing it abandoned and being unable to contact the developers, I decided to build my own alternative.
In case you're curious about how the system works under the hood, here’s a simplified explanation of the current architecture:
How ZetaShare works (simplified):
The sender uploads a file on the website. The server doesn’t store the file — After uploading, the sender receives a 6‑digit ID. This ID becomes the identifier for the transfer session.
The receiver opens the link with the ?id= parameter, for example: https://zetashare.com/?id=123456
When the receiver joins the link, the server sends the receiver’s SDP offer to the sender. (This is part of the WebRTC signaling process.)
The sender responds by sending back their own SDP answer.
Both sides then exchange ICE candidates through the server.
After the WebRTC handshake is complete, a direct P2P connection is established between sender and receiver — and the file starts transferring directly between the two devices.
So the server is only used for:
exchanging SDP offer/answer
relaying ICE candidates …and nothing else. No file, no metadata, no tracking.
Once the WebRTC connection is established, all data flows peer‑to‑peer, fully outside the server.
What works now:
WebRTC P2P transfers — files go directly between users.
No metadata collection — unlike other services that send file metadata through signaling servers (like ToffeeShare), our server only handles SDP and ICE candidates.
No accounts required — just drag, drop, and share.
Unlimited file sizes.
Completely free — no ads at all.
What’s missing (in my view):
Only TLS (WebRTC’s built-in), no proper end-to-end encryption yet.
No password protection.
Links will have an expiration option soon.
Mobile file transfer speed needs improvement.
Coming next:
Password protection
File expiration option
Mobile performance improvements
Proper end-to-end encryption
Try it out: https://zetashare.com
These are the features I could think of, but if you have better ideas, I’d love to hear them. I can’t promise to build everything, but I’ll definitely try.
I’m using AI to help me because my English isn’t perfect — sorry if it sounds a bit AI-generated!