Last updated: 2026-07-03
Snapdrop and its actively maintained fork PairDrop are pioneers of browser-based, install-free file sharing. They are polished, familiar, and genuinely good tools — Relayium builds on the same idea rather than dismissing it.
This article compares the three fairly: what they share, where Snapdrop and PairDrop are stronger, and where Relayium is different. The short version is that Relayium's focus is encryption strength and reaching across networks, not replacing what already works well on your LAN.
All three run entirely in a modern web browser with nothing to install, and all three use WebRTC to move file bytes directly between two devices instead of parking them on a server.
On the same local network they can discover nearby devices automatically, so sending a photo from a laptop to a phone in the same room is a couple of taps in any of them.
Snapdrop has been around for years and has a large, trusting community; PairDrop extends it with features Relayium does not try to match today.
Plain WebRTC is encrypted in transit by DTLS, and that is real protection against a passive network eavesdropper. But the DTLS fingerprints that authenticate each side are exchanged through the signaling server. A malicious or compromised signaling server can substitute its own fingerprints and sit invisibly in the middle — a classic man-in-the-middle attack that DTLS alone does not stop.
Relayium adds a second, independent encryption layer on top of the WebRTC channel: an X25519 key exchange derives a key used for per-chunk AES-256-GCM, and that key is never sent to any server. To detect a man-in-the-middle, both devices display the same 6-digit Short Authentication String (SAS); if the codes match, no server sits between you. Each file is also verified end-to-end with a SHA-256 hash.
Relayium is designed to work across networks, not only on the same Wi-Fi. You can connect two devices with a pairing code or a share link, and the transfer still goes directly peer-to-peer whenever possible.
When a direct connection is impossible, the encrypted stream falls back to a TURN relay — but the relay only ever sees ciphertext, so the transfer stays end-to-end encrypted. There is also an optional stored download-link mode: your browser encrypts the files with AES-256-GCM and the decryption key lives only in the URL fragment, so the server stores zero-knowledge ciphertext it cannot read. Realtime transfers need no account; creating a share or download link requires the sender to sign in. Transfers that drop mid-way can resume instead of restarting.
The differences that matter most, side by side:
For quick sharing between devices on the same network, any of them works well. If you need to reach across different networks or you want an extra, server-independent encryption layer with a verification code, Relayium is aimed at that; if you love PairDrop's rooms and persistent pairing, it remains an excellent choice.
Yes. Relayium is MIT-licensed and the full protocol and code are public at github.com/relayium/relayium, so you can audit it or run your own instance — the same openness that made Snapdrop and PairDrop trusted.
In practice, no meaningful one. All three make a direct WebRTC connection, so throughput is bounded by your network. Relayium's extra AES-256-GCM layer runs in the browser and its overhead is negligible next to the network transfer itself.
See how the application-layer encryption feels in practice — no install, no account needed for realtime transfers.
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