Debug School

Cover image for Install Syncthing
Suyash Sambhare
Suyash Sambhare

Posted on

Install Syncthing


Check the Community Contributions which let you pick a flavor of Syncthing that best fits your scenario. For cross-platform GUI applications, you can check out Syncthing-GTK. There are also Windows, Android, and many more specific flavors.

Syncthing Releases

For Debian/Ubuntu use the Debian repository.
For Windows, there will be a binary called syncthing.exe.

At first start, Syncthing will generate a configuration file, and some encryption keys and then start the admin GUI in your browser. Something like the following will be printed in the command line:

> syncthing
[monitor] 22:56:32 INFO: Log output saved to file "C:\Users\User\AppData\Local\Syncthing\syncthing.log"
[monitor] 22:56:32 INFO: Default folder created and/or linked to the new config
[start] 22:56:32 INFO: syncthing v1.7.1 "Fermium Flea" (go1.14.4 windows-386) 2020-07-11 18:17:41 UTC
[start] 22:56:32 INFO: Default folder created and/or linked to new config
[start] 22:56:32 INFO: Default config saved. Edit C:\Users\User\AppData\Local\Syncthing\config.xml to taste (with Syncthing stopped) or use the GUI
[6FOKX] 22:56:34 INFO: Single thread SHA256 performance is 123 MB/s using crypto/sha256 (108 MB/s using minio/sha256-simd).
[6FOKX] 22:56:34 INFO: Hashing performance is 106.31 MB/s
[6FOKX] 22:56:34 INFO: Overall send rate is unlimited, receive rate is unlimited
[6FOKX] 22:56:34 INFO: Using discovery server
[6FOKX] 22:56:34 INFO: Using discovery server
[6FOKX] 22:56:34 INFO: Using discovery server
[6FOKX] 22:56:34 INFO: Ready to synchronize "Default Folder" (default) (send receive)
[6FOKX] 22:56:34 INFO: QUIC listener ([::]:22000) starting
[6FOKX] 22:56:34 INFO: TCP listener ([::]:22000) starting
[6FOKX] 22:56:34 INFO: Relay listener (dynamic+ starting
[6FOKX] 22:56:34 INFO: Completed initial scan of send receive folder "Default Folder" (default)
[6FOKX] 22:56:34 INFO: GUI and API listening on
[6FOKX] 22:56:34 INFO: Access the GUI via the following URL:
[6FOKX] 22:56:34 INFO: My name is "This computer"
[6FOKX] 22:56:45 INFO: quic:// detected NAT type: Symmetric NAT
[6FOKX] 22:56:45 INFO: quic:// resolved external address quic:// (via
[6FOKX] 22:56:46 INFO: Detected 0 NAT services
Enter fullscreen mode Exit fullscreen mode

At this point, Syncthing will also have set up a folder called Default Folder for you, in a directory called Sync in your home directory (%USERPROFILE% on Windows). You can use this as a starting point, then remove it or add more folders later.


The admin GUI starts automatically and remains available on http://localhost:8384/. Cookies are essential to the correct functioning of the GUI; please ensure your browser accepts them.

On the left is the list of “folders”, or directories to synchronize. You can see the Default Folder was created for you, and it’s currently marked “Unshared” since it’s not yet shared with any other device. On the right is the list of devices. Currently, there is only one device: the computer you are running this on.

For Syncthing to be able to synchronize files with another device, it must be told about that device. This is accomplished by exchanging “device IDs”. A device ID is a unique, cryptographically secure identifier that is generated as part of the key generation the first time you start Syncthing. It is printed in the log above, and you can see it in the web GUI by selecting “Actions” (top right) and “Show ID”.

Two devices will only connect and talk to each other if they are both configured with each other’s device ID. Since the configuration must be mutual for a connection to happen, device IDs don’t need to be kept secret. They are essentially part of the public key.

To get your two devices to talk to each other click “Add Remote Device” at the bottom right on both devices, and enter the device ID of the other side. You should also select the folder(s) that you want to share. The device name is optional and purely cosmetic. You can change it later if desired.

Once you click “Save” the new device will appear on the right side of the GUI (although disconnected) and then connect to the new device after a minute or so. Remember to repeat this step for the other device.

At this point, the two devices share an empty directory. Adding files to the shared directory on either device will synchronize those files to the other side.


If you are using a Syncthing flavor that adds OS-specific functionality (e.g. the Android app), you may need to access the Web GUI to enable syncing folders and other configuration options.

Congratulations! 👍🐉🦴
You have successfully setup and configured Syncthing.


Top comments (0)