How to Use Your Spare Laptop as a Second Monitor
Transform your old laptop into a functional secondary display using software or hardware adapters.
1Maximizing Existing Hardware
Adding a second monitor significantly enhances multitasking by providing more visible tabs and workspace. Instead of purchasing new hardware, users can repurpose spare laptops as secondary screens. This process requires checking device compatibility and choosing between wireless software solutions or wired hardware adapters to achieve either mirrored or extended display configurations.
2Windows Wireless Casting
Windows 10 and 11 systems utilize Miracast technology for wireless display connections. Users must enable the Wireless Display feature in system settings and open the app on the secondary device. By pressing Windows key plus K on the primary machine, users can select the spare laptop and input a security PIN.
3Apple Ecosystem AirPlay
Mac users can leverage AirPlay to connect devices if the MacBook is a 2018 model or newer. Both devices must be signed into the same Apple ID for the connection to function. Users configure this via System Settings under AirDrop Continuity, allowing the primary Mac to detect the secondary screen as an extension.
4Cross-Platform Software Solutions
Connecting different operating systems, such as Windows to Mac or Linux, requires third-party tools like Deskreen. This open-source software operates over Wi-Fi by generating a QR code or URL for browser-based connection. To extend the display rather than just mirroring, users often need a virtual display adapter, commonly called a dummy plug.
5Wired Connection Limitations
Standard laptop HDMI ports are designed for video-out, meaning direct cable connections between two laptops will not function. To bypass this, users must employ an HDMI-to-USB video capture card. This hardware converts the signal, allowing the secondary laptop to receive the primary device's feed as if it were a webcam input.
6Managing Latency Issues
Wireless methods, while convenient for presentations or web browsing, often introduce noticeable lag due to Wi-Fi transmission speeds. Consequently, these wireless setups are generally unsuitable for competitive gaming or high-frame-rate tasks. Wired capture card solutions typically offer lower latency, making them a more reliable choice for demanding visual applications or console gaming.
7Software for Wired Feeds
When using a capture card, the secondary laptop treats the incoming signal as a camera feed. Users can view this display using built-in camera applications or professional software like OBS Studio. This approach works across Windows, Mac, and Linux, providing a versatile method to bridge different operating systems for display purposes.
8Alternative Hardware Utility
If repurposing a laptop as a monitor does not meet your specific workflow needs, consider other functional roles for older hardware. Many users successfully convert spare machines into dedicated smart home hubs or media servers. These alternatives ensure that older devices remain productive assets within a modern digital home environment.