How to control two Macs with one keyboard and mouse

With MacDisplay 3.0, move the pointer toward the edge of one screen and simply continue onto the other Mac. Once it crosses over, your keyboard follows it: click a window, start typing, and keep working on the second computer using the same input devices.

Both Macs remain completely independent. Each continues to run its own macOS environment, apps and files, with its own desktop. MacDisplay simply allows your mouse and keyboard to move naturally between them.

That's the key difference from Extend Display. With display extension, the screen of the second Mac becomes additional workspace for your main computer. With Keyboard & Mouse, both Macs remain separate computers — you simply control them from the same desk.

Move between Macs without changing input devices

The feature is designed to feel natural. If your second Mac is positioned to the right of your main screen, move the pointer toward that edge and simply keep going onto the other computer.

From that point, mouse movements, clicks and keyboard input are directed to the Mac you're controlling. There's no button you need to press every time you switch computers and no new interaction to learn.

This is particularly useful when both computers are an active part of your workflow. You might have a project open on one MacBook while another MacBook, Mac mini, Mac Studio or another Mac is running different tools, documents or tasks. You can keep working across both without filling your desk with duplicate input devices.

Keyboard & Mouse and File Transfer work together

The connection becomes especially useful when Keyboard & Mouse is combined with File Transfer.

Both features can run at the same time. That means you can control two Macs from the same mouse and keyboard while also moving files directly between them over the wired connection.

You can keep MacDisplay's transfer drop area on your Desktop as an always-available place to send files. When you need something on the other computer, simply drag it onto the drop area and start the transfer. On the receiving Mac, you can also choose where incoming files should be saved — for example, directly on the Desktop or inside a specific project folder.

This creates a particularly natural workflow. You may be working on the first Mac, move the pointer onto the second and continue working there, then realise you need a document, video or folder that is still on the first computer. Drop it into MacDisplay and send it directly across without interrupting what you're doing.

File Transfer runs over Thunderbolt or Ethernet and can therefore take advantage of very high wired speeds. With recent Macs and fast SSDs, both computers can work side by side almost like parts of the same workspace while still remaining completely independent systems.

It's one of the most useful combinations in MacDisplay 3.0: one mouse and keyboard for working across both Macs, plus a direct high-speed path for moving files between them.

Copy on one Mac, paste on the other

MacDisplay can also share the clipboard between your Macs.

When you enable it, copy text or other content on one computer and paste it directly on the other using the familiar copy-and-paste workflow.

Clipboard sharing is optional, so you decide whether to use it.

Together, the features complement each other well. The clipboard handles the small things you want to move instantly — a link, some text, a command or an address — while File Transfer handles the documents, folders and larger files that actually need to be stored on the other Mac.

You decide which Mac is allowed to connect

Letting one Mac control another requires a clear trust relationship between the two computers.

The first time two Macs are paired, MacDisplay displays a six-digit code on both screens. Check that the numbers match and approve the connection.

Communication between the computers is protected with end-to-end AES-256-GCM encryption. When a new Mac asks to control yours for the first time, you decide whether to allow it.

Those permissions remain available inside MacDisplay and can be reviewed or changed later. Once that trust relationship has been established, everyday movement between your Macs can remain immediate.

Wired when you can, Wi-Fi when you need it

Keyboard and mouse control can use the direct wired connection between your Macs. If you're already using Thunderbolt or Ethernet with MacDisplay, control can travel over that same link without adding anything else to your setup.

Unlike File Transfer, however, Keyboard & Mouse can also work over Wi-Fi when you choose to enable it. That can be useful when a cable isn't available or when you want a more flexible setup.

Wi-Fi is slower than a wired connection, while communication remains protected with the same encryption.

And when you're connected to a public network or simply don't want MacDisplay using Wi-Fi at all, you can enable Lockdown mode.

Lockdown mode when you're using public Wi-Fi

Hotels, airports, universities, coworking spaces and shared offices often mean connecting to a Wi-Fi network you don't directly control. MacDisplay 3.0 introduces Lockdown mode especially for situations like these.

Turn it on and MacDisplay forcibly excludes Wi-Fi from its own communications, using only the wired connection between your Macs.

That does not mean you have to turn Wi-Fi off on the computer. You can stay online and keep using the network normally for browsing, email and other apps. MacDisplay itself remains isolated from the wireless network.

Keyboard and mouse control and MacDisplay's other communications stay on the wired connection. The setting is remembered after you quit and reopen the app, so you don't have to enable it again each time.

Keyboard & Mouse and File Transfer pause when you extend the display

There's one important distinction to know. Keyboard & Mouse and File Transfer can run together, but both are disabled while Extend Display is active.

That's intentional.

When another Mac is being used as a true second monitor, its display is dedicated to the desktop of your main computer. In that situation, controlling the second Mac's own desktop at the same time would not be useful because its screen is already being used by the extended display session.

MacDisplay also keeps this mode separate so Extend Display can have the stability it needs without other activities competing with the display session.

The two workflows are therefore clear: use Extend Display when you want the second Mac to become an additional monitor, or use Keyboard & Mouse + File Transfer together when you want both Macs to remain fully active as independent computers.

Keyboard and mouse control or a second monitor?

The choice simply depends on what you want the two Macs to do at that moment.

If you want the display of the second Mac to become extra space for the windows running on your main computer, use Extend Display. You're working on one Mac with a larger desktop.

If you want both computers to remain independent, each with its own apps and files, you can use Keyboard & Mouse and File Transfer together.

The second Mac does not need to play a secondary role. It might be a recent MacBook, a desktop Mac or another computer you actively use every day. When both Macs are on the same desk, MacDisplay simply gives them a more direct way to work together.

Only the Mac starting the action uses the allowance

The free version follows a simple rule: only the Mac initiating a feature uses its allowance.

A Mac being controlled does not consume Keyboard & Mouse time. A Mac receiving files does not use file-transfer credit. A Mac acting as a display does not consume display-extension time.

That means a Mac running the free version of MacDisplay can be controlled without limits, receive files without limits, or act as a display without limits. Usage limits apply only to the Mac sending its display, controlling another Mac, or sending files.

For Keyboard & Mouse, the controlling Mac uses 10-minute usage blocks, followed by a 60-second wait, with up to 60 minutes of total usage per day, shared with Extend Display. Disconnecting and reconnecting does not reset the current block.

For File Transfer, the free allowance applies to the sending Mac: up to 2 GB per day, with a maximum of 2 GB in a single transfer. The receiving Mac can receive without limits and does not use its own allowance.

A full MacDisplay license removes these limits from the Macs initiating those actions, and one license covers three Macs.

Two Macs, one workspace

This is where the new features in MacDisplay 3.0 really change the way two computers can work together.

Both Macs can remain completely independent, running different apps, files and tasks, while you move between them simply by continuing the pointer across the edge of the screen. Your keyboard follows, the clipboard can follow, and when you need to move an actual file, you can drop it into MacDisplay and send it directly to the other computer over the cable.

Keyboard & Mouse and File Transfer are designed to work together because they serve the same scenario: two active Macs sharing one workspace.

When you need more room for the windows of a single computer instead, switch to Extend Display and MacDisplay dedicates the second Mac to that task.

With MacDisplay 3.0, you decide how your Macs work together.

MacDisplay Team MacDisplay Published on 21 September 2026

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