Written for Synergy 3 (v3.8.4) and Synergy 1 (v1.22.3), checked 20 October 2026.
Install Synergy 1 or Synergy 3 on each of your computers, with all of them on the same network, then connect them as below. What you need, and the installation guides: Start here: Install and configure
In Synergy 3, your computers find each other, and you add one by its address only when it doesn't appear. In Synergy 1, each client connects to the server by the server's name or IP address.
Synergy 3
Open Screen layout on any of your computers. Your other computers running Synergy 3 on the same network appear there on their own, while Auto discover at the top of the page is on (it is by default). Then choose the computer whose keyboard and mouse you share, and arrange them. For the steps, see: Arranging your computers
The first time two computers connect, both show a code. Check that it's the same on both screens, then click Codes match on both computers. More about this check: Encryption and verifying your computers
Add a computer by its IP address or hostname
If a computer doesn't appear on your Screen layout by itself, add it by its address:
- On the computer you want to add, open Synergy 3 and go to Screen layout.
- Click This computer's details.
- Note one of the addresses under This computer's IP addresses are:, or the Hostname:.
- On another computer, click Add computer (under Connections). You can also get there from Manage computers > Manually add computer.
- Type the IP address. To use a hostname instead, click the three-dot menu next to the box and choose Switch to hostname.
- Wait for Ready to appear beside the address.
- To add more than one computer, click Add computer below the box and enter the next address.
- Click Connect computer (Connect 2 computers, and so on, when you've entered several). 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: Which ports to open in a firewall
- Serial key mismatch: the two computers use different serial keys. Enter the same serial key on both. For the steps, see: Entering or changing your serial key
- Error: something went wrong in Synergy 3 itself. Send us a diagnostic report: Getting diagnostic info and logs
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.
Synergy 1
Choose one computer to be the server: the one with the keyboard and mouse you want to share. Every other computer is a client, which connects to the server by the server's name or IP address.
Start the server
- On the server, select Use this computer's keyboard and mouse (make this computer the server).
- Click Start.
The first time the server starts, a Synergy Server message confirms it's running and tells you to watch for a prompt on the server when a client connects.
The top of the window shows This computer's name: and, below it, the server's IP address (Suggested IP:). If the computer is connected to more than one network, hover over the address to see the others. You need the name or the address to connect each client.
Connect each client
- On the client, select Use another computer’s mouse and keyboard (make this computer the client).
- In the Connect to: box, type the server's computer name or IP address.
- Click Connect.
Use the server's computer name if you can. Type the server's computer name (shown next to This computer's name: on the server, above its IP address) instead of its IP address. The server's IP address can change, for example when your router gives it a new one, and the client then can't connect until you type the new address in. The computer name keeps working when the address changes. Synergy 1 starts with the name the computer has on your network; if you changed the name in Synergy 1, type the IP address instead. Synergy 3 doesn't need this step: it finds computers on the same network by itself when an address changes.
If the client is a Mac and the name stops working, see: How to fix a server hostname that stops resolving on macOS
Accept the client on the server
With TLS encryption on (the default with a business license or Synergy 1 Pro), the first connection asks you to compare fingerprints:
- On the client, a Connecting to a new server window asks Do you want to connect to the server?
- On the server, unless Require client certificates is turned off in its preferences, a New client connecting window asks Trust client and allow connection?
Check that the fingerprints match on both computers, then click Yes on each. How to compare them, and how to turn encryption on: Encryption and verifying your computers
Then the server offers to add the new client to its layout:
- If you compared fingerprints on the server, a message says A new client called '...' has been accepted. Click OK.
- Otherwise, the server asks A new client called '...' wants to connect. Click Add client.
The Server Configuration window opens with the client already placed beside the server. Drag it to where it sits on your desk, then click OK. More about the layout: Arranging your computers
The first time the computers connect, a Synergy Connected message appears, and the client's status bar shows Synergy is connected as client of followed by the name or address you typed in Connect to:.
Still can't connect?
Run a ping test between the computers: How to do a ping test
Check that a firewall isn't blocking Synergy 1 or Synergy 3. The ports they use: Which ports to open in a firewall
On macOS 15 or later, Synergy 1 and Synergy 3 need the macOS Local Network permission: Can't connect on macOS 15 or later: allowing local network access