How to sync a folder between two computers with Syncthing (step by step)

Syncthing keeps a folder identical on two devices without a cloud service. Follow these steps to connect two computers.

1. Install Syncthing on both computers and start it.
2. Open the web interface on each computer at http://127.0.0.1:8384.
3. Copy the Device ID from Actions > Show ID on the first computer.
4. Add the device on the second computer with the Add Remote Device button, and paste the ID.
5. Accept the request on the first computer when it appears.
6. Share a folder. Edit the folder on one computer, open the Sharing tab and tick the other device, then accept the folder on the second one.