node-mac-virtual-display: Native Library for Virtual Display on macOS

A native library for macOS to create virtual displays for your applications using Node.js. This library uses CoreGraphics and CoreDisplay APIs to provide an interface for creating and managing virtual displays on macOS. This library is used in Tab Display, a service that allows iPads and Android tablets to be used as portable monitors.

Features

• [x] Create and Destroy single virtual displays on macOS.
• [x] Configurable display resolution and refresh rate.
• [x] Create a virtual display by cloning the main display.
• [x] Added option to select between Mirror and Extend display modes
• [ ] Support for multiple virtual displays.

Requirements

• macOS 10.14 or later
• Node.js 12 or later

Installation

Use npm to install the library:

yarn add node-mac-virtual-display

Cross-platform projects

This package declares "os": ["darwin"], so package managers know it only applies to macOS. If your project also builds on Windows or Linux, declare it as an optional dependency:

{
  "optionalDependencies": {
    "node-mac-virtual-display": "^1.0.15"
  }
}

Both parts are needed. With optionalDependencies, the os field makes package managers skip the download and the node-gyp build entirely on non-macOS platforms. Listed under regular dependencies, the os field alone does not prevent installation — the package is still fetched and the native build still runs, and fails.

Guard the require at runtime too, since the module will be absent on other platforms:

let VirtualDisplay = null
if (process.platform === 'darwin') {
  VirtualDisplay = require('node-mac-virtual-display')
}

Importing the types has the same constraint: import type still makes TypeScript resolve the .d.ts, which fails on platforms where the package was skipped. Declare the shape you need locally instead.

Usage

To create/destroy a virtual display:

const VirtualDisplay = require('node-mac-virtual-display')
const vdisplay = new VirtualDisplay()
// Clone primary display
vdisplay.cloneVirtualDisplay({
  displayName: "Clone Display",
  mirror: true
})
// OR
// To create a virtual display:
vdisplay.createVirtualDisplay({
  width: 1920,
  height: 1080,
  frameRate: 60,
  hiDPI: true,
  displayName: "Virtual Display",
  mirror: false
})

//To destroy a virtual display:
vdisplay.destroyVirtualDisplay()

Persistent Display Identity

This library now automatically uses the Display Name (displayName) as the persistent identity key.

• Name-Based Persistence: When you create a display with displayName: "My Monitor", it receives a consistent internal ID derived from that name.
• Mac Memory: macOS will remember the window layout and resolution settings associated with that specific name.
• Simple Usage: Just use the same name next time, and your windows will be exactly where you left them.

⚠️ Note on Changing Resolutions

If you keep the same displayName but drastically change the resolution or aspect ratio (e.g., 16:9 -> 4:3), macOS might get confused because it thinks it's the same monitor. If you need a "fresh" monitor profile, simply give it a new name (e.g. "Monitor V2").

Contribute

Coffee fuels coding ☕️