OtterDrop: send files between phone and computer over Wi-Fi
share files with the devices around you
Paddling into the lodge, one moment.
About OtterDrop
Files go straight from one device to the other.
If your phone and your laptop are on the same Wi-Fi, they can hand files to each other without a cable, a cloud account or an app. Open this page on both and they find each other. Share a file on one, take it on the other. It works between iPhone, Android, Windows, macOS and Linux, in any combination.
- 01Open the page on two devices
Every device on your network lands in the same room. From a phone, the quickest way in is to scan the QR code on the other screen — that works whether or not the phone is on the same Wi-Fi. For someone further away, send the link or read out the four-character room code.
- 02Share a file
Drop it on the page. It shows up in the list on every device in the room, but nothing has been sent yet. Sharing just announces the file.
- 03Take it on the other device
Tap the file, or Download all. It comes directly from the device that shared it, at Wi-Fi speed. Any type of file, any size.
Underneath it’s WebRTC, the same encrypted peer-to-peer connection that browser video calls use. A small signalling service passes the connection handshake between devices so they can find each other. It never sees a file. No server keeps anything and there is no history. Close the tab and what you shared is gone. A room takes up to eight devices.
Questions and troubleshooting
I don't see the other device
Devices find each other automatically when they share a Wi-Fi network. If they don’t — a VPN, or a guest network that keeps devices apart — scan the QR code, or type the other screen’s room code under Enter a code. If you see “Could not reach the room server”, the network is blocking the connection. Reconnect and refresh.
Can I send to someone in another city?
Yes — send them the link, or read them the four-character room code to type under Enter a code. It opens the same room, and the file still goes straight from your device to theirs; it is never uploaded to us. That is also the catch: we don’t run a relay to fall back on, so if either network blocks direct connections (some office Wi-Fi, some mobile carriers) the two devices can’t connect at all.
A device shows “adrift”, or a download fails
The two devices couldn’t connect to each other directly. Hotel, guest and office Wi-Fi often block that on purpose, and we have no relay to route around it — that is the price of files never touching our servers. Try a phone hotspot or a home network.
Who can join with my room code?
Anyone who has it, from any network — that is the point of it, and the reason it is worth treating like a door key rather than a label. It is only good while the room is: once every device has closed the page there is nothing left to join, and the code lapses on its own and can end up belonging to somebody else’s room.
A transfer stops partway
The file comes straight from the device that shared it, so that device has to keep this page open until the download is done. Locking a phone can pause its browser, too.
Can anyone on my Wi-Fi see my files?
Anyone on the same network can join the room, see the names of the files on offer, and take them. At home that’s the point. On a busy shared network, look at the device names before you take something, and don’t share what you wouldn’t want the room to see. Nobody outside the two devices in a transfer can see the file contents.
Does it need the internet?
Only briefly, to set things up. The files themselves go over your local Wi-Fi. A home router or a phone hotspot is enough.
Step-by-step: sharing files between your phone and computer. OtterDrop is part of ottercraft.dev, a few small free tools that run in your browser.