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Add a computer by its IP address or hostname in Synergy 3

Updated

Written for Synergy 3 (v3.7.2), checked 3 October 2026.

If a computer doesn't appear on your Screen layout by itself, add it by its address:

  1. On the computer you want to add, open Synergy 3, go to Screen layout and click This computer's details. Note one of the addresses under This computer's IP addresses are:, or the Hostname:.
  2. On another computer, click Add computer (under Connections). You can also get there from Manage computers > Manually add computer.
  3. Type the IP address. To use a hostname instead, click the three-dot menu next to the box and choose Switch to hostname.
  4. Wait for Ready to appear beside the address.
  5. To add more than one computer, click Add computer below the box and enter the next address.
  6. Click Connect computer (or Connect with the number of computers). The Screen layout opens with the new computer on it.

What the status beside the address means

  • One moment...: Synergy 3 is checking the address.
  • Ready: Synergy 3 can reach the computer. You can connect.
  • Failed: nothing answered at that address. Hover over it to see why. Check that Synergy 3 is installed and open on that computer, that both computers are on the same network, and that a firewall isn't blocking Synergy 3. The ports it needs are listed in: What ports does Synergy use?
  • Serial key mismatch: the two computers use different serial keys. Enter the same serial key on both. For the steps, see: Enter or change your serial key in Synergy 3
  • Error: something went wrong in Synergy 3 itself. Send us a diagnostic report: How to get diagnostic info?

The three-dot menu next to each box also has Clear and, when there's more than one box, Delete.

No addresses listed?

If This computer's details says We could not find any active connections., connect the computer to a network first. If it shows a note starting IP address for network device:, Synergy 3 is set to one network interface; to see all addresses, set Network interface to Auto in Local networking.

Still can't connect?

Run a ping test between the computers: How to do a ping test

On macOS 15 or later, the firewall can block the connection: macOS 15 Sequoia firewall breaks network connection