How to Use a Laptop as a Monitor: Wireless, Software and Capture Options

You can use a laptop as a monitor, but usually not by running an HDMI cable into it. On almost every laptop the HDMI port is an output: it sends the laptop's picture to a TV or monitor and cannot receive one. To show another device's picture on a laptop screen, you need one of four routes instead: built-in wireless projection, a screen-sharing app, a USB video capture device, or remote desktop software.

Which one makes sense depends on what you want to display and how much delay you can live with.

Why the HDMI port won't do it

A monitor contains circuitry that accepts a video signal and drives the panel with it. A laptop's video hardware is built the other way round: its graphics chip creates an image and sends it to the internal screen or out through the port. Connecting two laptops with an HDMI cable therefore links two outputs, and nothing appears. The same applies to most USB-C ports that carry video. A handful of devices are designed with video input, but unless the manual says so, assume your laptop has none.

Option 1: wireless projection built into the system

Recent versions of Windows can receive a screen over a wireless display connection. The setup in outline:

1. On the laptop that will act as the screen, open the system settings and look for Projecting to this PC. If it is greyed out, install the optional Wireless Display feature first.
2. Choose who can project and whether a PIN is needed.
3. On the other Windows computer, open the Cast or Connect panel and select the laptop from the list.
4. Pick Extend to use it as a second desktop, or Duplicate to mirror.

Recent versions of macOS offer something similar: supported Macs can act as an AirPlay receiver, so another Apple device can mirror or extend to them. Both approaches need the devices on the same network and both hardware and drivers that support the feature.

Wireless projection is fine for documents, slides, photos and browsing. There is a noticeable delay, so fast games and precise mouse work can feel sluggish.

Option 2: a second-screen app

Several apps turn a laptop into an extra display for another computer. You install a small server program on the main machine and a viewer on the laptop, then connect over your home network or, with some apps, a USB cable. The main computer treats the laptop as an added monitor you can drag windows onto.

This route works across different operating systems and is handy for a portable two-screen setup. Picture quality and delay depend on your network and on how hard the app compresses the image, so a wired connection usually beats wireless.

Option 3: a USB capture device

For a game console, a camera or a streaming box, the most reliable route is an HDMI-to-USB capture device. These small adapters were made for recording and streaming video, and they work as a monitor substitute:

1. Connect the console or camera's HDMI output to the capture device.
2. Plug the capture device into a USB port on the laptop, ideally a fast one.
3. Open a camera app or video-capture software; the device appears like a webcam.
4. Select it, set the resolution to match the source, and go full screen.

Cheap capture sticks add a small delay that casual players may never notice, while more expensive ones aim for lower lag and higher frame rates. Some sources, such as certain streaming devices, block capture of protected content, so you may see a black screen with films from paid services. The same family of hardware is used for saving old home movies; our guide on how to convert VHS to digital covers that use.

Option 4: remote desktop

If what you want is to see and control another computer from the laptop, rather than add a screen, remote desktop software is the simpler tool. Windows editions that include it can be reached from another computer, and many third-party apps do the same across systems. It is good for reaching a desktop in another room, less so for video or games.

Which method suits which job?

Common mistakes

• Buying an HDMI cable and expecting it to work. It only helps the other way, laptop to TV.
• Running wireless setups on a busy network. Video traffic competes with everything else; move closer to the router or use a cable where you can.
• Ignoring power settings. A laptop that sleeps after a few idle minutes drops the connection, so adjust sleep settings while it serves as a screen.
• Mismatched resolution. Set the source to the laptop screen's native resolution, or the picture may look soft.

Is it worth it?

For an occasional second screen or a console in a guest room, a laptop does the job well enough. For daily use, a cheap external monitor is simpler and has no delay. And when the goal is simply a good picture for streaming, sending the laptop's own output to a bigger screen is the more natural direction, as our piece on smarter streaming on every screen explains. Planning a long evening in front of it? Our movie marathon ideas help with themes, breaks and snacks.