Written for Synergy 3 (v3.7.2), checked 3 October 2026.
Install Synergy 3 on each of your computers, then open Screen layout on any one of them. Your other computers appear there on their own, and anything you change is shared with all of them.
Choose the computer that shares its keyboard and mouse
- On the Screen layout, click the three-dot menu on the computer whose keyboard and mouse you want to use.
- Click Make this primary.
The primary computer shows a mouse badge (its tooltip reads Controls the keyboard and mouse). The first-run tutorial calls this option "Use this keyboard and mouse"; it's the same thing. Your license is activated on the primary computer only. For details, see: How license activation works in Synergy 1 and Synergy 3
Arrange and resize your computers
- Drag each computer so its edge touches the computer next to it, where you want the cursor to cross. Computers snap together when you drag them close.
- Drag a computer's edge or corner to resize it, so the touching edges match where your screens really meet.
Synergy 3 saves the layout as soon as you let go. A computer with several monitors is one rectangle on the layout. For uneven monitor arrangements, see: Multiple monitor and custom monitor positioning support
The computer menu
Click the three dots on a computer, on the Screen layout or on the Manage computers page:
- Make this primary: share this computer's keyboard and mouse (not shown on the computer that's already primary).
- Computer preferences: name, modifier keys, dead corners and other per-computer options.
- Retry connection: reconnect to a computer that shows as unreachable (not shown on the computer you're using). If Synergy 3 doesn't know its address yet, a Can't connect yet message offers Try again and Connect manually.
- Remove computer: take the computer off your layout.
What the icons on each computer mean
Hover over the small icons on a computer to see its status:
- Keyboard/mouse connected or Keyboard/mouse not connected: whether keyboard and mouse sharing is working with this computer.
- Service reachable or Service unreachable: whether this computer's Synergy 3 background service can be reached over the network. If it's unreachable, try Retry connection, then: How to do a ping test
Auto discover
Auto discover, at the top of the Screen layout, finds other computers running Synergy 3 on your network. It's on by default. If a computer doesn't appear, add it by its address from Add computer.
Messages on the Screen layout
- Computers overlap. Drag the computers apart so none sits on top of another.
- Computers have the same name. Rename one in Computer preferences.
- No primary computer selected. Choose one with Make this primary.
- The current license only allows a number of computers: remove computers with Remove computer, or move to an edition that allows more. Synergy 3 Lite allows 3 computers, Synergy 3 Plus 5, Synergy 3 Max 15 and Synergy Business has no limit.
- Connection from an address rejected due to serial key mismatch. Enter the same serial key on every computer: open License, then use Update all computers. For the steps, see: Enter or change your serial key in Synergy 3
- Connection from an address rejected due to incompatible version. Install the same version of Synergy 3 on every computer.
- On a Mac, a warning about Apple Wireless Direct Link (AWDL): click Turn off AWDL and enter your Mac password to stop the stutter it causes, or Don't warn about AWDL to hide it. More about lag: What to do when the mouse cursor lags?