Send files between devices on the same Wi-Fi

Last updated: 2026-08-07

If two or more devices are on the same Wi-Fi or local network, sending a file between them should not require an account, a code, or a trip through the cloud. Relayium detects when devices share a network and lets them connect directly, in the browser, with nothing to sign up for.

This guide covers the generic same-network case — any devices, any operating systems, even more than two at once. If you have a specific device pair in mind, see the dedicated guides for PC to phone, Mac to Windows, or an AirDrop-style flow for Windows/Linux/Android linked at the end.

How same-network detection works

Relayium does not ask you to type anything to find nearby devices. When your browser opens relayium.com without a pairing code, the server places you in a room based on the network you are connecting from — in practice, devices that share the same public IP address (the same home, office, or campus Wi-Fi, or the same mobile hotspot) land in the same room automatically.

That room is not capped at two participants: it holds however many devices open the site from that network, so a whole desk of laptops or a classroom of phones can all see each other at once, not just a single pair.

Step by step

Before you start

Every device on the same Wi-Fi or local network, with the router not keeping its clients apart. Relayium's own hint under the device list names the setting to look for: “AP isolation / client isolation”.
A current browser on each device (Chrome, Edge, Firefox or Safari) with the page open over https://relayium.com/. Encrypted transfer needs HTTPS, and over plain http:// the page says exactly that instead of listing devices.
No account and no pairing code. Same-network discovery asks for neither, on either side, so there is nothing to set up before the first transfer.
Somewhere for the files to land on the receiving device. Which place that is belongs to the receiving browser and its operating system, not to us: Chrome and Edge on a computer can ask you where to save, and other browsers write to their own Downloads folder. You confirm where they landed in that browser's own downloads list — chrome://downloads in Chrome, edge://downloads in Edge, about:downloads in Firefox.

The whole flow happens in the browser — no app to install on any device.

Connect every device you want to use to the same Wi-Fi or local network, then open the transfer page on each of them.
```
https://relayium.com/
```
Read the status pill under the heading on both devices and compare the public IP in it. One shared address is what puts two devices in the same room; two different addresses mean two different networks, whatever the Wi-Fi name says.
```
Connected · this device MacBook · public IP 203.0.113.9
```
Look under “Nearby devices”. Every device that opened the page from that network is listed there as a card carrying its own name — nothing to type, nothing to confirm.
On the sending device, click the recipient's card and press “Open workspace”. On a current browser that is the single action a nearby-device card offers, because files, folders and messages all travel over the one encrypted connection it opens. The room may list several devices; opening a workspace is how you pick the one this transfer goes to, and you open another one when the next person's turn comes.
The workspace replaces that card. Read the connection off its header from now on — who you are connected to, the link state, and the one path badge — and use the controls under it to send: “Send files” for a batch, “Send a folder” for a whole tree where the browser offers folder picking, or type into the message box and press “Send”. One file batch carries up to 1,000 files.
On the receiving device the request arrives with the file count and the total size, and the line under it says what pressing “Accept” will do — either the browser asks where to save, or the files go to its Downloads folder. Press “Accept” to start.
Watch the file counter reach the last file on both screens. If you want to compare a verification code (SAS) before anything moves, turn on “Advanced verification” on both devices first: it is off by default, and switching it on adds a comparison and an approval step rather than encryption — the transfer is encrypted either way.

What a working transfer looks like

The peer card is gone by then — the workspace took its place. The state is in the workspace header instead: the device you are connected to, a link state of “Connected”, and one path badge reading “LAN direct”, a host-to-host hop across your own network. “P2P direct” is the honest second case: the two devices really did share a public IP, but the hop their browsers settled on was not a local one.

On the receiving side the counter ends on the last file, and the file itself is wherever the save line said it would be. The receiving browser's own downloads list is where you confirm that, not this page — chrome://downloads in Chrome, edge://downloads in Edge, about:downloads in Firefox.

Connected to MacBook · Connected · LAN direct
File 3/3

A same-network room is not capped at two devices, so a card for every phone and laptop in the room is normal rather than a sign that something went wrong.
Nothing here is uploaded first and downloaded afterwards, so there is no copy on a server to pick up later: both devices stay on the page until the counter finishes.

When the devices don't see each other

Same-network discovery keys off the network your browser is connecting from, so that is where to look first: the two devices are not really on one network, the router is keeping its clients apart, the page was not opened over HTTPS, or the receiving browser is being asked to hold more than it can. Those are common first checks rather than the whole list, and each of them has something on screen that decides it.

Symptom, check, fix

“Nearby devices” stays empty, or lists only the device you are looking at.

https://relayium.com/   # open it on both, then compare the public IP in the status pill

Two different public IP addresses mean two separate rooms. A VPN, iCloud Private Relay, or a guest SSID that sends clients out through another address are common reasons for that, and not the only ones. If you are willing to change them: switch the VPN off, or turn Private Relay off for that one Wi-Fi network, or move both devices onto the main network, then reload https://relayium.com/ on each. If you would rather leave them on, a pairing code on https://relayium.com/cross-network reaches the other device without touching either setting, and is end-to-end encrypted the same way.

Both devices show the same public IP and still neither card appears.

https://relayium.com/   # the hint under the device list names the router setting

The router is separating its own clients. Turn off “AP isolation / client isolation” in its Wi-Fi settings — mesh systems, hotel and guest networks often ship with it on — and reload the page on both devices. When you do not control the router, a pairing code on https://relayium.com/cross-network is the way through instead.

The page says encrypted transfer requires HTTPS, and no device list appears at all.

https://relayium.com/   # the address bar has to read https, not http

The page was opened over http:// or by raw IP address, so the browser withholds the APIs an encrypted transfer needs. relayium.com itself redirects to HTTPS, so this normally means a self-hosted instance reached over http:// — open it as https://relayium.com/, or give your own instance a certificate.

The receiving device warns, before you accept, that it has to hold the whole batch in memory.

chrome://downloads   # in Chrome; Edge has edge://downloads and Firefox about:downloads

That browser cannot stream a download straight to disk, so it buffers the batch and a large one may end in a crashed tab. Receive it in Chrome or Edge on a computer, or send fewer files at a time, and check each arrival in the receiving browser's own downloads list — chrome://downloads in Chrome, edge://downloads in Edge, about:downloads in Firefox — rather than assuming it saved.

The transfer runs, but the badge reads “P2P direct” instead of “LAN direct”.

https://relayium.com/   # read the path badge in the workspace header

The two devices share a public IP without sharing a local hop — carrier-grade NAT, two VLANs behind one uplink, or an extender in client mode all do this. The transfer is still direct and still end-to-end encrypted; put both devices on the same access point if you want the path to be your LAN rather than whatever route the browsers found.

Why it is fast: no server in the middle

Both devices connect from the same network, so Relayium links them peer-to-peer: the bytes go from one device to the other without a round trip to a Relayium server, and there is nothing to upload first and nothing to wait on downloading afterwards. How fast that is depends on the hop the two browsers actually settled on, and the path badge names it. “LAN direct” is the local one — the data stays inside your own network and runs at your network's speed rather than your internet connection's. “P2P direct” is still direct and still has no server in the middle, but the route the browsers found left the local segment, so it is bounded by whatever link it really crosses. A shared public IP is what puts two devices in the same room; on its own it is not a promise that the hop between them is local.

This is also why no account is involved on either side: with everyone already on the same trusted network, Relayium does not need sign-in to know who should be allowed to connect to whom.

Still end-to-end encrypted

Being on the same network does not mean the transfer is sent in the clear. Relayium negotiates an X25519 key exchange between the two devices and encrypts every chunk with AES-256-GCM; that key is never seen by any server, including Relayium's own signaling server, which only helps the devices find each other. With advanced verification on, both screens also display a short verification code (SAS) that lets you visually confirm the connection is genuinely between your two devices, and each file is checked end to end with a SHA-256 hash so you know it arrived byte-for-byte intact.

On different networks: pairing and relay

The server generates exactly six decimal digits (0–9, including a leading zero). The sender signs in to create the code, while the person joining by code, link or QR never needs an account. It accepts new joins for five minutes; an already connected transfer is not cut off when that countdown ends.

Across networks, browsers use an encrypted TURN relay by design rather than trying a direct path first. The key stays on the two devices, so the relay forwards only end-to-end-encrypted ciphertext, cannot read the files and keeps no realtime content copy or history.

Frequently asked questions

Do I need an account to send files on the same Wi-Fi?

No. Same-network transfers need no account and no pairing code on either side — just open relayium.com on each device.

How does Relayium know which devices are on my network?

Devices that connect from the same network typically share the same public IP address, and Relayium groups devices with a matching public IP into the same room automatically, with no code required.

Can more than two devices see each other at once?

Yes — the room lists every device that opens relayium.com from that network, so a phone, a laptop and a desktop all appear side by side. A transfer itself is one-to-one: you open a workspace with one of the listed devices, and that is who the files go to. Sharing with several people in the same room means opening a workspace with each of them in turn.

Is the transfer still encrypted if it never leaves my network?

Yes. Every same-network transfer uses the same X25519 key exchange and AES-256-GCM encryption as a cross-network one, with a verification code you can check yourself and a SHA-256 integrity check per file.

What if one device is on Wi-Fi and the other is on mobile data?

They are not on the same network, so automatic discovery will not connect them. Use a pairing code instead — the sender signs in to create it, and the receiver does not need an account. Across networks the transfer runs over an encrypted TURN relay rather than a direct connection, and it stays end-to-end encrypted throughout: the relay only forwards ciphertext and cannot read the file.

Open Relayium on any two (or more) devices on the same Wi-Fi and send your first file — no account, no code needed.

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