How to use one keyboard and mouse on Windows and Mac

A Windows PC and a Mac on the same desk usually means two keyboards, two mice, and a lot of reaching. A hardware KVM switch solves part of that, but it moves your monitor along with your input and it knows nothing about your clipboard.

DeskAcross takes the software route. Both computers keep their own screens. You move the pointer off the edge of one screen and it arrives on the other computer, and the keyboard follows it.

One thing first. Keyboard and mouse sharing is still in development, and the app labels it Experimental. The steps below describe how it works today. Expect it to change, and keep each computer's own keyboard within reach while you try it.

What you need

• DeskAcross installed and running on both computers.
• Both computers on the same local network.
• Local network sync turned on. Keyboard and mouse sharing is built on top of it.

If you have not set up sync yet, the Quick Start covers it in a few minutes. In short: open Sync → Device Sync on each computer, turn on Sync Between Devices, set the same Sync Passphrase on both, then turn on Sync over Local Network under Sync → Local Network. Your operating system may ask for local network or firewall permission.

Step 1: Turn on sharing

On each computer, open DeskAcross settings and go to Keyboard & Mouse → Keyboard & Mouse Sharing. Turn on Share Keyboard and Mouse.

The other computer appears under Devices once it has been confirmed as one of your sync devices.

Step 2: Decide who controls whom

Control is not automatically mutual. Each device in the list has two separate permissions.

If your main keyboard is plugged into the Windows PC and you want to reach the Mac with it, turn on I can control it for the Mac on the PC. If you also want the Mac's trackpad to reach the PC, allow the other direction too.

Separate permissions are useful when one of the machines is a work laptop that should accept input but never send it, or the reverse.

Step 3: Arrange your screens

DeskAcross needs to know where the computers sit relative to each other so the pointer leaves one screen at the right place.

1. Open Keyboard & Mouse → Screens and select Arrange next to Screen Arrangement.
2. In Arrange Screens, drag one computer's group of screens next to the other's.
3. Line up the edges where you want the pointer to cross.
4. Select Save.

A few details make this easier:

• Edges cross, corners do not. Two screens must share part of an edge. Touching at a corner creates no crossing.
• Screens on the same computer stay together. They keep the arrangement set in the operating system, so you move each computer's displays as a group.
• Sizes are physical. Screens are drawn in proportion to their real size, which helps when a 27-inch monitor sits beside a laptop display. A ≈ symbol marks a size the monitor did not report.
• Arrow keys nudge. Select a computer and use the arrow keys to fine-tune its position. Hold Shift for larger steps.

Below the layout, the Crossings list shows each shared edge and the range it covers on both computers. A working crossing is drawn as a green line and listed as Working.

Step 4: Test it

Move the pointer across the shared edge. It should appear on the other computer, and typing should land there too.

To take control back on a computer, type on its own keyboard.

If the pointer does not cross

Work through these in order:

1. Check that local network sync and Share Keyboard and Mouse are both on, on both computers.
2. Confirm the other computer appears under Devices and the direction you are trying is allowed.
3. Open Arrange Screens and check that the two computers share an edge along the part of the screen you are using. A crossing that only covers the top half of an edge will not work from the bottom half.
4. Review Crossings and save the layout again after any change.

The full reference is in Share a Keyboard and Mouse.

Where copy and paste fits in

Sharing input is half of a two-computer desk. The other half is moving content. Because sharing runs on the same sync connection, text, images, and files you copy on one computer are available in clipboard history on the other, within the limits you set under Sync → What Syncs. See Copy and paste between Windows and Mac for how that works.

Plans and availability

On the pricing page, keyboard and mouse sharing and the visual screen arrangement editor are listed as In development. They are planned for Pro, with up to 3 computers, and Business, with no computer limit. They are not part of the Free plan.

Clipboard history and local network sync are available today. You can download DeskAcross, set up sync, and try sharing while it is experimental. If something does not behave the way this guide describes, tell us. Reports from real desks are what move a feature out of experimental.