You can use a laptop as a second monitor for a desktop PC, but your laptop must support video input
Most laptops cannot be used as monitors because their screens only display output from the laptop's own graphics card. The video port on your laptop — HDMI, USB-C, or DisplayPort — is designed to send video out to an external monitor, not to receive video in from another computer. To use a laptop as a monitor, you need either a laptop with a video input port (rare in consumer models) or software that streams the desktop image over your network.
The practical routes are: buy a USB-C docking station with video input if your laptop supports it, use wireless screen mirroring software, or connect via a capture card and USB. Each method has different speed, image quality, and cost trade-offs. Your choice depends on whether your laptop model supports video input natively, how far away the laptop will sit from your PC, and whether you need the connection to be wired or wireless.
Key Takeaways
- Most consumer laptops cannot receive video input through their ports, so you cannot straightforward plug a cable from your PC into your laptop's HDMI or USB-C port and see the desktop.
- Some newer laptops with Thunderbolt 3 or USB-C ports support video input mode, but you must check your laptop's manual or manufacturer specs to confirm.
- Wireless software like Spacedesk, Duet Display, or Windows 10/11 wireless projection can stream your PC desktop to your laptop over Wi-Fi or USB, though with slight lag.
- A USB video capture card connected to your laptop can receive HDMI output from your PC, but adds cost and uses a USB port.
- If your laptop does not support video input and you need a true second monitor, an external USB monitor or standard display is faster and more reliable.
Check whether your laptop has a video input port
Before you buy cables or software, determine whether your laptop can receive video input at all. Most laptops cannot. Check your laptop's user manual or the manufacturer's website for the specifications of your exact model. Search for terms like "video input", "input mode", or "external display input".
Laptops that support video input are uncommon and usually high-end models. Some newer MacBook Pro models with Thunderbolt 3 or Thunderbolt 4 ports can receive video input when connected to the right docking station. Some business-class laptops from Dell, Lenovo, or HP may support it through USB-C or Thunderbolt. Consumer-grade laptops from most brands do not. If your manual does not mention video input capability, your laptop almost certainly cannot receive video this way.
Use wireless screen mirroring software for a network connection
Spacedesk is the most common free option. Install the server software on your PC and the client app on your laptop. Both devices must be on the same Wi-Fi network. Open the app on your laptop, select your PC from the list, and the PC desktop appears on your laptop screen. The connection is wireless, so you can place your laptop anywhere in range. The image updates with a slight delay — usually 100 to 300 milliseconds — which is noticeable if you are moving the mouse quickly but acceptable for static work like reading documents or spreadsheets.
Duet Display is a paid option (around $10 to $20 depending on platform) that offers lower latency than Spacedesk and better color accuracy. It works over Wi-Fi or USB. If you connect via USB, the latency drops further and the connection is more stable, but you lose the freedom to place the laptop far from the PC.
Windows 10 and Windows 11 include a built-in wireless projection feature. On your PC, open Settings > System > Display > Multiple displays, then select "Connect to a wireless display". On your laptop, swipe in from the right edge (or press Windows Key + A) to open the Action Center, select "Connect", and choose your PC. This method is free but often slower and less reliable than Spacedesk or Duet.
Connect via USB video capture card if your laptop lacks video input
A USB video capture card is a small device that plugs into your laptop's USB port and accepts HDMI input from your PC. The PC sends video to the capture card via HDMI cable, and the capture card relays that video to your laptop through USB. Software on your laptop (usually included with the capture card) displays the video in a window.
This method is wired, so your laptop must stay within a USB cable's length of the PC — typically 10 feet or less. Latency is usually 50 to 150 milliseconds, which is faster than wireless software but still noticeable. Capture cards cost $30 to $100 depending on resolution and frame rate. They work with any laptop that has a USB port, regardless of whether it supports video input natively. The trade-off is that you lose a USB port and must manage an extra cable.
Use a docking station with video input if your laptop supports it
If your laptop has Thunderbolt 3, Thunderbolt 4, or USB-C with video input support, a docking station designed for your laptop model can receive HDMI or DisplayPort input from your PC and display it on your laptop screen. Thunderbolt docking stations are expensive — typically $150 to $300 — and you must buy one that matches your laptop's port type and manufacturer.
Before you buy a docking station, confirm in your laptop's manual that it supports video input mode. Not all USB-C or Thunderbolt docking stations have this feature. Once connected, the video appears on your laptop screen with minimal latency, usually under 50 milliseconds. This is the fastest method if your laptop supports it, but it is also the most expensive and requires your specific laptop model to have the capability.
Compare the methods by speed, cost, and setup
| Method | Latency | Cost | Setup | Best for |
|---|---|---|---|---|
| Spacedesk (wireless) | 100–300 ms | Free | Install app on both devices, same Wi-Fi | Casual use, documents, spreadsheets |
| Duet Display (wireless or USB) | 50–150 ms (USB), 100–200 ms (Wi-Fi) | $10–$20 | Install app, connect via USB or Wi-Fi | Better color, lower lag than Spacedesk |
| Windows wireless projection | 150–400 ms | Free (built-in) | Open Action Center, select PC | Quick temporary connections |
| USB capture card | 50–150 ms | $30–$100 | Plug into USB, run HDMI from PC | Wired setup, any laptop |
| Docking station with video input | Under 50 ms | $150–$300 | Plug into Thunderbolt/USB-C port | Fastest option, if laptop supports it |
When to buy an external monitor instead
If your laptop does not support video input and you plan to use a second display regularly, a dedicated external monitor is usually the better choice. A basic 24-inch USB monitor costs $100 to $200, connects via a single USB-C cable to your PC, and offers no latency, full brightness and color accuracy, and no software overhead. A standard HDMI monitor costs $80 to $150 and requires only an HDMI cable and power.
Using your laptop as a monitor works in a pinch — when you need a second screen temporarily and already have the laptop nearby. But if you are setting up a permanent workstation, the speed, reliability, and image quality of a real monitor outweigh the convenience of using hardware you already own. Laptops are designed to be portable, and their screens are optimized for that use. Repurposing one as a stationary display often means accepting lag, reduced brightness, or the need to keep the laptop plugged in and running software in the background.
Frequently Asked Questions
Can I use any laptop as a monitor for my PC?
No. Most laptops cannot receive video input through their ports. You can use wireless software like Spacedesk to stream your PC desktop to any laptop over Wi-Fi, but this introduces lag. Only laptops with Thunderbolt 3, Thunderbolt 4, or USB-C video input support can display video from another computer through a direct cable connection.
What is the fastest way to connect a laptop as a monitor?
A docking station with video input is fastest if your laptop supports it, with latency under 50 milliseconds. A USB video capture card is the next fastest option at 50 to 150 milliseconds and works with any laptop. Wireless software is slowest at 100 to 400 milliseconds depending on the app and network.
Do I need to install software on my PC to use my laptop as a monitor?
It depends on the method. Wireless software like Spacedesk requires you to install a server app on your PC and a client app on your laptop. A USB capture card requires software on your laptop only. A docking station with video input typically requires no software — it works like a standard monitor once plugged in.
Will using my laptop as a monitor drain its battery?
Yes. Displaying video from another computer uses power, and your laptop will drain faster than normal. For any extended use, plug your laptop into power. Wireless methods drain the battery faster than wired methods because the Wi-Fi radio stays active.
Is there lag when I use my laptop as a monitor?
Yes, unless you use a docking station with video input on a laptop that supports it. Wireless software introduces 100 to 400 milliseconds of lag. USB capture cards introduce 50 to 150 milliseconds. This lag is noticeable when moving the mouse or scrolling but acceptable for static tasks like reading or typing.