Having a dual-monitor setup can drastically improve productivity, whether you’re working from home, editing videos, or simply browsing the web. But what if you don’t have a spare monitor lying around? The good news is, you might already have one: your laptop! While laptops are primarily designed as standalone devices, there are several methods you can employ to repurpose them as external displays. This guide will walk you through the various options, explaining the technical aspects and providing step-by-step instructions to get you up and running.
Understanding the Basics: Why Isn’t It Always Plug-and-Play?
Before diving into the solutions, it’s crucial to understand why connecting your laptop as an external monitor isn’t as simple as plugging in a cable. Standard laptop ports like HDMI and USB are typically designed for outputting video from the laptop, not receiving it. Think of it like a one-way street; the laptop is built to send the video signal out, not to accept one in.
The underlying reason lies in the hardware and software configurations. Laptops generally lack the video input circuitry needed to process an incoming video signal from another device. This input circuitry is what traditional monitors possess, allowing them to interpret and display the incoming data.
Therefore, simply connecting two laptops with an HDMI cable, in most cases, won’t work. However, there are clever workarounds and dedicated software solutions that can bridge this gap.
Option 1: Using Software Solutions – The Remote Desktop Approach
One of the most versatile methods for using your laptop as an external display involves remote desktop software. These applications allow you to remotely control one computer from another, essentially mirroring or extending the display of the primary device onto the secondary laptop.
Understanding Remote Desktop Protocols
Remote desktop connections rely on specific protocols to transmit data between the two computers. The most common are RDP (Remote Desktop Protocol), VNC (Virtual Network Computing), and proprietary protocols used by specific software. RDP is often built into Windows operating systems, while VNC is an open-source and cross-platform alternative.
The choice of protocol can impact performance, security, and compatibility. RDP generally offers better performance on Windows networks, while VNC is more flexible for connecting different operating systems.
Setting Up Remote Desktop on Windows
Windows operating systems have a built-in Remote Desktop feature, making it a convenient option for Windows-to-Windows connections.
Enabling Remote Desktop on the Host Computer (The Computer Whose Screen You Want to Extend)
First, you need to enable Remote Desktop on the computer that will be sharing its screen. This is the host computer.
- Search for “Remote Desktop Settings” in the Windows search bar and open it.
- Toggle the “Enable Remote Desktop” option to “On.”
- You might be prompted to confirm your choice. Accept the confirmation.
- Pay attention to the user account information displayed. You’ll need this information to connect from the other laptop. If no users are listed, add the user accounts that you want to allow remote access. Make sure those user accounts have passwords set.
- (Optional) For added security, configure the firewall settings to allow Remote Desktop connections. This is usually done automatically, but you may need to manually configure it if you are using a custom firewall.
Connecting from the Client Laptop (The Laptop Acting as the Monitor)
Next, you need to connect to the host computer from the laptop you want to use as the external monitor. This is the client laptop.
- Search for “Remote Desktop Connection” in the Windows search bar and open it.
- In the “Computer” field, enter the name or IP address of the host computer. To find the IP address of the host computer, open Command Prompt on that machine and type
ipconfig. Look for the IPv4 address. - Click “Show Options” to configure additional settings, such as display resolution and local resources (printers, clipboard).
- Enter the username and password for the user account you enabled for Remote Desktop on the host computer.
- Click “Connect.”
Once connected, the screen of the host computer will be displayed on the client laptop. You can then configure Windows to extend the display, effectively using the laptop as a second monitor.
Configuring Display Settings for Extended Desktop
After successfully connecting via Remote Desktop, you’ll likely want to configure the display settings to extend the desktop rather than simply mirroring the screen.
- On the host computer, right-click on the desktop and select “Display Settings.”
- In the “Multiple displays” section, choose “Extend these displays” from the dropdown menu.
- Arrange the virtual monitors to match your physical setup. You can drag the monitor icons to position them correctly.
- Click “Apply” to save the changes.
Now, you should be able to move windows and applications seamlessly between the main monitor and the laptop screen.
Using Third-Party Remote Desktop Software
While Windows Remote Desktop is a solid option, several third-party remote desktop applications offer enhanced features, cross-platform compatibility, and improved performance. Popular choices include:
- TeamViewer: Known for its ease of use and comprehensive feature set, including screen sharing, file transfer, and remote control.
- AnyDesk: Praised for its speed and low latency, making it ideal for tasks that require real-time responsiveness.
- Chrome Remote Desktop: A free and simple option for connecting to computers through the Chrome web browser.
The setup process for these applications is generally similar. You’ll need to install the software on both the host and client computers, create an account (if required), and follow the instructions to establish a connection. Most of these programs will guide you through the process.
Option 2: Using a Wired Connection with Display Emulation Software
Although direct HDMI input is rare on laptops, some software solutions can effectively “trick” the computer into recognizing a connected device as an external monitor. These solutions often involve installing a driver or application that emulates a display.
How Display Emulation Works
Display emulation software works by creating a virtual display adapter on the client laptop. This virtual adapter mimics the behavior of a physical monitor, allowing the operating system to recognize it as a potential display target. When the host computer connects to the client laptop, it sends the video signal to this virtual display, which the software then renders on the laptop screen.
Spacedesk: A Popular Display Emulation Solution
Spacedesk is a well-regarded application that enables you to use your Android tablet, smartphone, or even another computer as an external monitor via a local network (Wi-Fi or Ethernet) or USB.
Installing and Configuring Spacedesk
The setup process involves installing two components:
- Spacedesk Driver Server: This is installed on the host computer (the one whose screen you want to extend).
- Spacedesk Viewer: This is installed on the client laptop (the one you want to use as the external monitor).
Download the appropriate versions of the software from the Spacedesk website and follow the installation instructions.
Connecting via Spacedesk
- Ensure that both the host and client laptops are connected to the same network (or connected via USB if supported).
- Launch the Spacedesk Driver Server on the host computer. It will display the server’s IP address.
- Launch the Spacedesk Viewer on the client laptop. It will automatically scan for available Spacedesk servers on the network.
- Select the host computer from the list of available servers.
- Click “Connect.”
Once connected, the client laptop will function as an external monitor. You can then configure the display settings on the host computer to extend the desktop, just like with Remote Desktop.
Benefits and Drawbacks of Display Emulation
Display emulation offers a few advantages over Remote Desktop:
- Lower Latency: Display emulation typically has lower latency than Remote Desktop, especially when connected via USB. This can make it a better option for tasks that require real-time responsiveness, such as gaming or video editing.
- Potentially Better Image Quality: Display emulation can potentially offer better image quality than Remote Desktop, as the video signal is not being compressed and re-encoded.
However, there are also some drawbacks:
- Compatibility Issues: Display emulation software may not be compatible with all hardware and software configurations.
- Driver Conflicts: Installing display emulation drivers can sometimes lead to driver conflicts or system instability.
- USB Support: USB connections are often limited to specific versions of Spacedesk and may require specific USB drivers.
Option 3: Hardware Solutions: Capture Cards (Rare and Often Overkill)
While less common and generally not the most practical solution for most users, capture cards offer a hardware-based approach to using your laptop as an external monitor.
How Capture Cards Work
Capture cards are devices that can capture video signals from external sources, such as gaming consoles, cameras, and, in theory, another computer. These cards typically connect to your computer via USB or an internal expansion slot.
To use a capture card to display the screen of another computer on your laptop, you would need to connect the output of the host computer (e.g., HDMI) to the input of the capture card. The capture card would then transmit the video signal to the laptop, where you can view it using the capture card’s software.
Why Capture Cards Are Not Ideal for Most Users
While capture cards can technically work, they are generally not the best solution for several reasons:
- Cost: Capture cards can be expensive, especially high-quality ones that support high resolutions and refresh rates.
- Latency: Capture cards can introduce latency, which can be noticeable when performing tasks that require real-time responsiveness.
- Complexity: Setting up a capture card can be more complex than using software solutions.
- Intended Use: Capture cards are primarily designed for recording and streaming video, not for general-purpose display extension.
Unless you already have a capture card for other purposes or have very specific requirements that cannot be met by software solutions, it is generally not recommended to purchase one solely for the purpose of using your laptop as an external monitor. The software options will be more cost-effective and less complex for most situations.
Troubleshooting Common Issues
Regardless of the method you choose, you may encounter some common issues when trying to use your laptop as an external monitor. Here are some troubleshooting tips:
- Connection Problems: If you are having trouble connecting, double-check that both computers are connected to the same network and that the necessary software or drivers are installed and running correctly. Verify IP addresses and firewall settings.
- Performance Issues: If you are experiencing lag or stuttering, try reducing the display resolution or refresh rate. Close unnecessary applications to free up system resources. Consider using a wired connection (Ethernet or USB) instead of Wi-Fi.
- Display Problems: If the image is distorted or not displaying correctly, check the display settings on both computers. Ensure that the resolution and refresh rate are compatible. Update your graphics drivers.
- Security Concerns: When using Remote Desktop or other remote access software, be aware of the security risks. Use strong passwords and enable two-factor authentication whenever possible. Keep your software up to date to patch any security vulnerabilities.
Conclusion: Choosing the Right Method for You
Using your laptop as an external monitor can be a convenient and cost-effective way to boost your productivity or create a more immersive gaming experience. While it may not be as straightforward as plugging in a traditional monitor, the software solutions available today make it relatively easy to achieve.
Consider your specific needs and technical expertise when choosing a method. If you primarily use Windows computers and need a simple solution, Windows Remote Desktop may be the best option. If you need cross-platform compatibility or enhanced features, a third-party remote desktop application like TeamViewer or AnyDesk might be a better choice. If you need lower latency and are willing to troubleshoot potential compatibility issues, Spacedesk or a similar display emulation application could be a good fit.
By carefully evaluating the pros and cons of each method, you can find the perfect solution for turning your laptop into a valuable external display.
Can I use any laptop as an external monitor?
Not all laptops can be directly used as external monitors. Most laptops are designed primarily to output video signals, not receive them. They lack the necessary video input ports (like HDMI in or DisplayPort in) required to accept and display video from another device. However, there are workarounds using software solutions, albeit often with limitations regarding latency and image quality.
Software solutions like spacedesk or Deskreen allow you to use your laptop as a secondary display over a local network. This method essentially streams the screen of your primary device to the laptop. Keep in mind that performance depends heavily on your network connection and the processing power of both devices involved. Latency can be noticeable, making it unsuitable for fast-paced gaming or video editing.
What hardware is required to turn a laptop into an external monitor?
The primary factor is the presence of a video input port on your laptop. Ideally, you’d need an HDMI-in or DisplayPort-in port. These ports are specifically designed to receive video signals. Unfortunately, they are relatively uncommon on laptops, particularly consumer models.
If your laptop lacks a video input port, you’ll need a compatible USB capture card or adapter. These devices convert the HDMI or DisplayPort output from your primary device into a format that can be read by your laptop via a USB port. The capture card then acts as a bridge, allowing your laptop to display the incoming video signal.
What software solutions are available, and how do they work?
Several software solutions are available, including spacedesk, Deskreen, and Twomon SE. These applications work by utilizing your local network to transmit the screen content from your primary device (the one you want to extend) to your secondary laptop (the one you want to use as an external monitor).
The primary device runs a server application that captures the screen and sends it over the network. The secondary laptop runs a client application that receives the screen data and displays it. The software effectively turns the laptop into a remote display, though performance is highly dependent on network speed and stability.
Are there any limitations to using software solutions for this purpose?
The biggest limitation is latency. Because the screen data is being transmitted over a network, there’s always some delay between the action on the primary screen and its appearance on the laptop screen. This latency can be significant, making it unsuitable for tasks requiring real-time responsiveness.
Another limitation is image quality. The video stream is often compressed to reduce bandwidth usage, which can result in a noticeable loss of detail, especially with fast-moving content. Also, the performance is highly dependent on the strength and stability of your local network. A weak or congested network can lead to stuttering, lag, and disconnections.
How does using a capture card differ from using software?
A capture card provides a more direct and generally higher-quality connection compared to software-based solutions. Capture cards physically convert the video signal from one device to another, minimizing latency and eliminating the need for a network connection.
This translates to significantly better performance for tasks that require real-time responsiveness, such as gaming or video editing. Furthermore, capture cards often support higher resolutions and refresh rates than software solutions, resulting in a sharper and more visually appealing display.
What are the key considerations when choosing a capture card?
Several factors should influence your choice of capture card. Consider the resolution and refresh rate you need to support. If you plan to use your laptop as an external monitor for gaming, ensure the capture card can handle the resolution and refresh rate of your gaming console or PC.
Also, pay attention to the input and output ports. Make sure the capture card has the necessary ports to connect to your primary device (e.g., HDMI or DisplayPort) and your laptop (typically USB). Finally, consider the price point, as capture cards range from relatively inexpensive to quite costly, depending on their features and performance capabilities.
What are the power consumption implications of using a laptop as an external monitor?
Using a laptop as an external monitor will inevitably increase its power consumption. This is true regardless of whether you are using a software solution or a capture card. The laptop’s display will be active, consuming power to illuminate the screen.
Additionally, the laptop’s processor and graphics card will be working to process and display the incoming video signal, further increasing power consumption. As a result, the laptop’s battery life will likely be significantly shorter than it would be under normal usage. Be sure to keep the laptop plugged into a power source for extended use.