I discovered a youtube video (published by an apparently legitimate and well-known youtube publisher named Kevin Stratvert) describing a quick method to transfer files between devices - iPhones, Android phones, Macs and Windows PCs. The devices must be on the same local network. The devices connect by accessing either of these two weblinks: snapdrop.net or sharedrop.io
Here is the link to the short (4 min) youtube video: https://www.youtube.com/watch?v=66kkARfXdx8
Can someone explain how this works? Is it safe to do this? Is there a way to accomplish the same result without accessing an out-of-network website?
The above weblink access would not be needed to transfer files from one Mac to another Mac on the same network; one would simply enable file sharing on the two Macs and use Finder to transfer files. Transferring files to or from IOS or Android devices require something different, such as the weblink methods above or installing an app. But is there another way using “local” resources only, and without installing a potentially dodgy app or accessing a potentially dodgy weblink?
Kevin Stratvert said this in a comment on that YouTube video.
When you enable file sharing on a Mac, it creates an SMB share. You can access that from, say, an iPhone. On the Mac, open Network Properties and make note of its IP address. Like this:
On the phone, open Files, tap the three dots at upper right, then Connect to Server.
Type in the IP address, tap Connect.
Select Guest or Registered User (with Name and Password you use to log into that Mac).
The Mac will now appear in the Shared list in Files.
I’m sure Android has similar capabilities. Maybe this, but I have no experience with Android.
If you want to do all this even outside your network, look into Tailscale, which is an easy to set up VPN based on Wireguard. After setup, the scenario is the same as above, except you use a different IP address, something like 100.75.36.23.
As @JayAgostino quoted, WebRTC transfers are peer-to-peer and totally safe. That’s why so many of those local transfer sites have been able to pop up in the last several years: they have almost zero operating costs since they aren’t handling any of your data.