Use a Windows laptop as a Mac monitor

Windows tools for using a laptop as a second screen, like Miracast or spacedesk, expect a Windows PC as the main computer. SpareScreen works the other way round: it runs on your Mac, and the Windows laptop just opens a link in its browser.

How to set it up

1. Install SpareScreen on your Mac with the line above. It opens in the menu bar.
2. Allow Screen Recording when macOS asks. That lets SpareScreen show the extra screen on your Windows laptop.
3. Open the link in Chrome or Edge. Click SpareScreen in the menu bar to see the link and its QR code, then open it on the Windows laptop. Both need to be on the same Wi-Fi.
4. Click Allow on the Mac. An extra screen appears, shaped exactly like your Windows laptop. Drag windows onto it like any monitor.

On the laptop, press F11 so Chrome or Edge fills the screen. Then put it left or right of your Mac in System Settings → Displays → Arrange.

Why nothing goes on Windows

SpareScreen creates the extra screen on the Mac and sends it to a web page. So there's no Windows app, driver or admin password involved, which also means a work laptop you can't install software on still works.

Good to know

• Stop Windows sleeping: Settings → System → Power → Screen and sleep → Never, while plugged in.
• Work laptops are fine: no admin rights are needed, because nothing is installed.
• Touch control is optional. Turn it on in the SpareScreen menu (it asks for Accessibility permission) to tap, drag, right-click and scroll on the device. Typing still happens on the Mac.
• Everyday work feels instant. Video and fast scrolling are heavier and can stutter on slow Wi-Fi; 5 GHz Wi-Fi helps.
• Streaming services stay black. Netflix, Prime Video and Disney+ block screen capture in every app like this.
• Use Wi-Fi you trust. The picture travels over your local network, never through the internet.

Questions

Can I use a Windows laptop as a second screen for a Mac?

Yes. SpareScreen runs on the Mac; the Windows laptop only opens a link in Chrome, Edge or Firefox on the same Wi-Fi.

Do I need to install anything on Windows?

No. The laptop just shows a web page, so there's no app or driver to install.

What does SpareScreen cost?

It's free for 7 days, then $7.99 once. It's a one-time purchase with no subscription, and one key works on up to 3 Macs.

Which Macs does it work on?

Any Mac running macOS 13 Ventura or later, with Apple Silicon or Intel.

More guides

• Use your iPad as a second monitor for Mac
• Use an Android tablet as a second monitor for your Mac (wireless
• Use an old laptop or Chromebook as a second monitor for your Mac
• Use your phone as a second screen for your Mac
• Sidecar alternative for iPads Sidecar doesn't support
• Sidecar not working or iPad not supported? Use any device as a Mac second screen
• Duet Display alternative with no subscription
• Luna Display alternative
• spacedesk for Mac? Here's what works on macOS instead
• Wireless second monitor for your MacBook
• Use a Chromebook as a second monitor for your Mac (wireless
• Use an Amazon Fire tablet as a second monitor for your Mac
• Use a Samsung Galaxy Tab as a second monitor for your Mac
• Add a second monitor to your Mac mini using a tablet or laptop you own
• Use an old iPad as a second monitor for your Mac (iPad Air 2
• Best ways to add a second screen to your Mac

Last updated October 2026.