In today’s digital age, the need for multiple monitors is becoming increasingly common. Whether you’re a programmer juggling code windows, a designer managing intricate projects, or simply someone who enjoys multitasking, having extra screen real estate can significantly boost your productivity. But what if you don’t want to invest in a traditional monitor? The question then arises: can you leverage that old laptop gathering dust in your closet and use it as a second monitor? The answer, thankfully, is often yes, but the process isn’t always straightforward. Let’s delve into the various methods and considerations involved in turning your spare laptop into a functional display.
Understanding the Possibilities: Why and When It Works
Before jumping into the “how,” it’s crucial to understand the fundamental principles at play. Laptops are designed primarily as standalone devices. They’re built to output video signals, not receive them. Traditionally, a direct video input port (like HDMI-in or DisplayPort-in) is absent. However, clever software solutions and, in some cases, specialized hardware can bridge this gap.
The idea of repurposing a laptop screen is appealing for several reasons: it saves money compared to buying a new monitor, it gives new life to older technology, and it’s a space-saving solution, especially in compact workspaces. The suitability of this approach depends heavily on your specific needs and the capabilities of both your primary and secondary laptops.
Think about the intended use. Is it for static reference materials, or will you be streaming high-definition video? The demands placed on the connection and the laptop’s processing power will influence the chosen method.
Key Considerations Before You Begin
Not all laptops are created equal. The age and specifications of your spare laptop will heavily influence its suitability as a secondary display. A very old machine with a slow processor and limited RAM might struggle to handle the demands of even basic screen sharing.
The operating systems of both laptops are also important. Windows, macOS, and even Linux offer different options and compatibility levels for screen sharing. Software solutions often require specific operating system versions to function correctly.
Finally, consider the connectivity options available. Both laptops need to be able to communicate, either via a wired connection (like Ethernet or USB) or wirelessly (via Wi-Fi). The speed and reliability of this connection will impact the responsiveness and overall experience.
Software Solutions: The Most Common Approaches
The most popular methods for using a second laptop as a monitor involve software applications that enable screen sharing or remote desktop functionalities. These solutions essentially allow your primary laptop to “stream” its display to the secondary laptop.
Using Windows’ Built-in Projecting Features
Windows offers a built-in feature called “Projecting to this PC” that can turn a laptop into a wireless display. This feature leverages the Miracast protocol, which allows devices to wirelessly stream audio and video.
To enable this feature on the secondary laptop (the one you want to use as a monitor), go to Settings > System > Projecting to this PC. You may need to install the “Wireless Display” optional feature. Configure the settings to your liking, such as whether a PIN is required for connection and whether the secondary laptop should always be discoverable.
On your primary laptop, press the Windows key + P to bring up the projection options. Select “Connect to a wireless display” and choose the name of your secondary laptop from the list of available devices.
While convenient, this method relies on a stable Wi-Fi connection and may experience some latency or lag, especially with demanding applications. It’s a good option for basic productivity tasks but might not be ideal for gaming or video editing.
Third-Party Screen Sharing Applications
Several third-party applications provide more robust and feature-rich screen sharing capabilities. Popular options include spacedesk, MaxiVista, and Twomon USB. These applications typically offer better performance and more customization options compared to the built-in Windows feature.
spacedesk, for example, allows you to use your Android tablet, smartphone, or even another computer as a secondary display via Wi-Fi or USB. It works by installing a server application on your primary laptop and a viewer application on the secondary device.
MaxiVista is another popular option that supports a wider range of features, including extending the desktop, mirroring the display, and even using the secondary laptop’s keyboard and mouse to control the primary laptop.
Twomon USB distinguishes itself by using a USB connection, which generally provides a more stable and faster connection compared to Wi-Fi. This can significantly reduce latency and improve the overall responsiveness of the secondary display.
When choosing a third-party application, consider the following: compatibility with your operating systems, performance (especially latency), features (such as touch screen support or keyboard/mouse sharing), and price (some applications are free, while others require a paid license).
Remote Desktop Software: An Alternative Approach
While primarily designed for remote access, remote desktop software like Microsoft Remote Desktop, Chrome Remote Desktop, and TeamViewer can also be used to repurpose a laptop as a monitor.
The key difference between remote desktop software and screen sharing applications is that remote desktop software essentially creates a separate user session on the secondary laptop. This means that the secondary laptop will be running its own instance of the operating system, independently of the primary laptop.
To use remote desktop software for this purpose, you would install the server component on the primary laptop and the client component on the secondary laptop. Then, you would connect to the primary laptop from the secondary laptop, effectively displaying the primary laptop’s desktop on the secondary screen.
This approach can be useful if you need to access specific applications or files that are only available on the primary laptop. However, it can also consume more resources and may introduce more latency compared to screen sharing applications. Remote desktop software can be effective, but is generally better suited for remote access rather than continuous use as a second monitor.
Hardware Solutions: A Less Common, But Sometimes Necessary Approach
While software solutions are generally the preferred method for using a second laptop as a monitor, there are some situations where hardware solutions may be necessary. These situations typically involve older laptops or specific use cases that require a more direct connection.
Using a USB to HDMI Adapter (with Limitations)
Some USB to HDMI adapters claim to allow you to use a laptop as a monitor. However, it’s crucial to understand that these adapters typically only work in one direction: from a computer with a USB port to a monitor with an HDMI port. They don’t typically allow you to input an HDMI signal into a laptop’s USB port and display it on the laptop’s screen.
There are some exceptions, but these are often specialized devices designed for specific purposes, such as video capture or signal processing. They are generally more expensive and require specific software drivers to function correctly.
It is important to carefully research and verify the capabilities of any USB to HDMI adapter before purchasing it for the purpose of using a laptop as a monitor. Most generic adapters will not work for this purpose.
External Video Capture Cards: A More Reliable (and Expensive) Option
A more reliable, though more expensive, hardware solution involves using an external video capture card. These devices are designed to capture video signals from external sources, such as cameras, game consoles, or other computers, and transmit them to a computer via USB.
To use a video capture card to repurpose a laptop as a monitor, you would connect the primary laptop’s HDMI output to the capture card’s HDMI input. The capture card would then connect to the secondary laptop via USB.
The secondary laptop would need to run software that can display the video feed from the capture card. Many capture cards come with their own software, or you can use third-party applications like OBS Studio.
This method provides a more direct and reliable connection compared to software-based solutions, but it also requires an additional hardware investment. External video capture cards are generally used by gamers and streamers, and can be overkill for simple productivity tasks.
Troubleshooting Common Issues
Regardless of the method you choose, you may encounter some common issues when trying to use a second laptop as a monitor. Here are some tips for troubleshooting:
- Connectivity problems: Ensure that both laptops are connected to the same network (if using Wi-Fi) or that the USB cable is securely connected. Check that the firewalls on both laptops are not blocking the connection.
- Latency or lag: Reduce the resolution or refresh rate of the secondary display. Close any unnecessary applications running on either laptop. Try using a wired connection instead of Wi-Fi.
- Compatibility issues: Make sure that the software or hardware you are using is compatible with the operating systems of both laptops. Update drivers and software to the latest versions.
- Display problems: Check the display settings on both laptops to ensure that the secondary display is properly configured. Try restarting both laptops.
Conclusion: Is It Worth It?
Using a second laptop as a monitor can be a viable solution for expanding your screen real estate, especially if you already have a spare laptop lying around. Software solutions are generally the easiest and most cost-effective option, but hardware solutions may be necessary in certain situations.
The key is to carefully consider your needs, the capabilities of your laptops, and the potential limitations of each method. Ultimately, the decision of whether or not to use a second laptop as a monitor depends on your individual circumstances and priorities. If you value convenience and cost savings, software solutions are a good starting point. If you need a more reliable and responsive connection, hardware solutions may be a better choice.
Can I simply plug my second laptop into my main laptop like a regular monitor?
No, you cannot directly connect a second laptop to your primary laptop and expect it to function as a standard external monitor via a simple HDMI or USB-C cable connection. While both devices have ports meant for video output (HDMI, DisplayPort, sometimes USB-C), they are primarily designed to transmit video from the laptop to an external display, not the other way around. Direct physical connection will not initiate the necessary signal reception protocols for the second laptop to act as a display.
Instead, you need to employ specific software or hardware solutions that enable screen sharing or mirroring, effectively turning the second laptop’s display into an extension of your main computer’s screen. These methods usually involve network connections (Wi-Fi or Ethernet) and specialized applications to facilitate the data transfer and display rendering, mimicking the functionality of a traditional monitor.
What software can I use to make a second laptop act as a monitor?
Several software options can facilitate using a second laptop as an external display. Some popular choices include spacedesk, Twomon SE, and Deskreen. These applications work by installing a server application on your primary laptop and a client application on the secondary laptop. The server application captures the screen data from your main laptop and streams it over the network to the client application running on the second laptop.
Spacedesk is a free option that works well for basic screen extension, while Twomon SE offers more advanced features like touch input support and better performance, but usually requires a paid license. Deskreen is a good option if you want to turn any device with a web browser into a second screen using a USB connection. The best option for you depends on your specific needs, budget, and operating systems.
What are the network requirements for using a second laptop as a monitor?
A stable and reasonably fast network connection is crucial for using a second laptop as a monitor, especially for demanding tasks like video editing or gaming. While Wi-Fi can work, a wired Ethernet connection generally provides a more reliable and faster link, reducing latency and improving overall performance. The network’s bandwidth will significantly impact the fluidity of the screen mirroring or extension.
Consider the resolution and refresh rate you plan to use on the second laptop. Higher resolutions and refresh rates require more bandwidth to transmit the screen data smoothly. Using a dual-band Wi-Fi router (2.4 GHz and 5 GHz) is recommended, and connecting both laptops to the 5 GHz band can further improve performance due to less interference compared to the 2.4 GHz band.
Will there be a performance impact on my main laptop if I use a second laptop as a monitor?
Yes, utilizing a second laptop as a monitor will invariably impose some level of performance impact on your main laptop. The process of capturing the screen data, encoding it, and transmitting it over the network consumes CPU and GPU resources. The extent of the impact depends on factors like the chosen software, the resolution and refresh rate of the extended display, and the capabilities of your primary laptop’s hardware.
Expect a slight decrease in overall responsiveness, particularly if you are running resource-intensive applications on your main laptop while simultaneously streaming its display to the secondary device. Lowering the resolution or refresh rate of the extended display can help mitigate this impact. Monitoring your CPU and GPU usage through the Task Manager (Windows) or Activity Monitor (macOS) can provide insights into the performance load.
Are there any hardware solutions for using a second laptop as a monitor?
While software solutions are common, dedicated hardware options exist for using a second laptop as a monitor, offering potentially better performance and a more seamless experience. Devices such as video capture cards or dedicated screen-sharing hardware can be employed. These devices allow you to connect your main laptop’s video output to the second laptop’s input, effectively treating it as a standard monitor.
These hardware solutions tend to be more expensive than software solutions, but they offer the benefit of reduced latency and lower CPU overhead on the primary laptop. This can be especially beneficial for tasks where responsiveness and smooth visuals are critical, such as gaming or professional video editing. The exact setup and compatibility vary depending on the specific hardware chosen.
What are the advantages of using a second laptop as a monitor?
Utilizing a second laptop as a monitor provides a convenient and cost-effective way to extend your screen real estate without investing in a dedicated external display. This can be particularly beneficial for multitasking, improved workflow, and enhanced productivity. It allows you to display multiple applications side-by-side, reference information while working on your primary task, or simply have more screen space for complex projects.
This setup is especially valuable when traveling or working in locations where carrying a traditional external monitor is impractical. By repurposing an existing laptop, you can create a portable and flexible multi-monitor setup, enhancing your productivity on the go. It avoids the need to purchase additional hardware if you already have a functional second laptop available.
What are the potential drawbacks of using a second laptop as a monitor?
Despite its benefits, using a second laptop as a monitor can present certain drawbacks. The most significant issue is typically the added latency compared to a dedicated external display. The process of capturing, encoding, transmitting, and decoding the screen data over a network introduces a delay that can be noticeable, especially in interactive applications like games or when precise cursor movements are needed.
Another potential disadvantage is the dependency on a stable network connection. Any fluctuations or interruptions in the network can disrupt the screen sharing, resulting in lag, stuttering, or disconnections. Furthermore, the image quality might not be as sharp or vibrant as a dedicated monitor, particularly when using lower-end software or experiencing network limitations. Finally, battery drain on both laptops may be accelerated depending on the chosen setup.