Want to use a spare laptop as an extra screen for your main PC? It’s possible, but probably not the way you’d expect. Here’s what works and what doesn’t.
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Why you can’t just use an HDMI cable
A laptop’s HDMI port is output only. It sends video out, but it can’t receive it. Plugging two laptops together with an HDMI cable does nothing. A very small number of laptops accept video input over USB-C, but almost all don’t. So the practical options are wireless or software-based.
Option 1: Windows “Projecting to this PC” (built in, free)
Uses Miracast over Wi-Fi. Both computers need Miracast-capable Wi-Fi, which is true of most laptops from the last several years.
On the laptop that will be the second screen:
- Go to Settings → System → Optional features → View features, search for Wireless Display, and install it.
- Go to Settings → System → Projecting to this PC and set it to Available everywhere on secure networks.
- Launch the Wireless Display app (search for it in Start).
On your main PC:
- Press Win + K (Cast) and select the laptop.
- Press Win + P and choose Extend.
It’s fine for documents, email and chat on the side, but there’s noticeable lag, so it’s no good for video or games.
Option 2: Spacedesk or similar apps (free, often better)
Apps like Spacedesk (free for personal use on Windows) send the display over your local network or a USB/Ethernet cable and are often smoother than Miracast. Install the driver on the main PC and the viewer on the second laptop. Duet Display (paid) works across Windows, Mac, iPad and Android.
Option 3: Mac and iPad
- Sidecar turns an iPad into a second Mac display (Control Center → Screen Mirroring).
- Universal Control lets one keyboard and mouse control a Mac and another Mac or iPad side by side, which is often more useful than an extended display.
Option 4: Share a keyboard and mouse instead
If you really just want to use both laptops at once, a tool like Microsoft’s free Mouse Without Borders (part of PowerToys) lets one keyboard and mouse move between two Windows PCs, copying and pasting across them.
Can I use my laptop as a monitor for Xbox, PS5 or Switch?
Not with an HDMI cable. As explained above, a laptop’s HDMI port only sends video out. Plugging a console into it does nothing (and won’t damage anything). Here’s what does work:
- Xbox: install the Xbox app on Windows and use Remote Play to stream your console to the laptop over your home network. A wired Ethernet connection on the console gives the best results.
- PlayStation 5: use Sony’s free PS Remote Play app for Windows or Mac. Sign in, and it streams your PS5 to the laptop with a DualSense controller.
- Nintendo Switch (or any HDMI device): a USB capture card (HDMI in, USB out) lets the laptop display the console’s video in an app like OBS Studio or the capture card’s viewer. There’s a small amount of lag, which is fine for casual play but not ideal for competitive games.
Remote Play quality depends on your Wi-Fi. For lag-free gaming, a cheap monitor or TV is still the better option.
The better solution: a cheap monitor
If you’ll do this every day, a real monitor gives you a sharp, lag-free image for less than you might think, and a portable USB-C monitor can travel with you. See how to connect a laptop to an external monitor.
