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Start Synergy 1 or Synergy 3 automatically at login

Updated

Written for Synergy 3 (v3.7.2) and Synergy 1 (v1.21.4), checked 3 October 2026.

Synergy 3

Synergy 3 starts automatically when you log in, with no setup needed. If it isn't running after you log in, contact our support team.

To use Synergy 3 on the login screen too, before anyone logs in, go to Local settings and turn on Run on the login screen. This is available on Windows and macOS. It isn't available on Linux, which doesn't let apps control the login screen.

Mac with FileVault turned on

After your Mac restarts, type your password on the Mac's own keyboard at the first login screen. FileVault asks for your password before macOS has fully started up, and Synergy 3 can't run until then.

If you need Synergy 3 to work on that first screen as well, you'll have to turn off FileVault. Before you do: turning off FileVault removes a layer of protection, so someone with physical access to your Mac no longer needs your password to get at your data. Weigh that trade-off before you turn it off.

  1. Choose Apple menu > System Settings.
  2. Click Privacy & Security in the sidebar.
  3. Click FileVault (you may need to scroll down).
  4. Turn off FileVault.
  5. Click Turn Off Encryption.

Once decryption has finished, restart your Mac to check that Synergy 3 works on the login screen.

Synergy 1

Synergy 1 starts sharing as soon as it opens, as long as it was running when it last closed. So to have it connect after every restart, make sure it opens at start-up and leave it running when you shut down.

Windows

The background service starts Synergy 1 for you when the computer starts, as long as it was running when you shut down. Check that it's turned on:

  1. Open Synergy 1 and go to Edit > Preferences.
  2. On the Advanced tab, check Use background service (daemon) (it's on by default).
  3. To also control the login screen and UAC prompts, check Always run as system (work at login screen and UAC).
  4. Click Save.

macOS and Linux

  1. Add Synergy 1 to your login items: macOS or Linux.
  2. Optionally, keep the window out of the way: go to Preferences (on macOS, in the Synergy menu; on Linux, Edit > Preferences), and on the Window tab, under When the application starts, choose Send to background. Click Save.

To run Synergy 1 at the Linux login screen, or as a service without the window, see: Running Synergy 1 before and after login on Linux

For a Raspberry Pi, see: How to start Synergy 1 or Synergy 3 at login on a Raspberry Pi

For the connection to come back by itself

  1. Give both computers a static IP address, so the address set in Synergy 1 doesn't change each time a computer restarts.
  2. Keep the computers on the same network. If you move either computer to a different location, you will need to reconfigure Synergy 1.
  3. Don't have a VPN connection active.

Shared computers: start Synergy 1 for every user on Windows

The background service already does this. Once Synergy 1 has been started on the computer, the service starts it again after every restart and keeps it running for whoever signs in, including at the login screen and on UAC prompts, without anyone opening the Synergy 1 window.

  1. Turn on Use background service (daemon) and Always run as system (work at login screen and UAC), as in the Windows steps above.
  2. Click Start in the Synergy 1 window once, so the service records what to run.

The service runs Synergy 1 with the settings of the account that last started it. To give every account on the computer the same settings, use the "All users" settings profile, described in: Configure Synergy 1 for multi-user support

More about the service and the login screen is in: How to make Synergy work with UAC prompts

Show the Synergy 1 window and tray icon for every user

The service doesn't open the Synergy 1 window or its tray icon. For every user to see them after signing in, add Synergy 1 to the startup folder that all users share:

  1. Open the installation folder, C:\Program Files\Synergy by default.
  2. Right-click synergy.exe.
  3. Choose Create shortcut (on Windows 11, choose Show more options first).
  4. When Windows offers to place the shortcut on the desktop, click Yes.
  5. Press Win + R.
  6. Type shell:common startup and press Enter.
  7. Move the shortcut from the desktop into the folder that opens.
  8. Sign out and back in to check that Synergy 1 opens.

To roll this out to many computers, create a Group Policy object that runs synergy.exe at login, assign it to an OU or user group, and test it with a non-admin account.

On macOS and Linux, Synergy 1 has no background service, so it starts only once a user signs in. Set it up for each user with the macOS and Linux steps above.

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