Can I use a laptop as second monitor for a different laptop?

Using a Laptop as a Second Monitor: Is It Possible and How to Do It?

When working remotely or on the go, maximizing your available hardware to boost productivity can be a game-changer. A common challenge many face is the lack of multiple monitors, especially when traveling or working outside the usual office setup. If you find yourself wondering whether it’s feasible to use a laptop as a second display for another device, you’re not alone. Let’s explore this scenario in detail and discuss potential solutions.

Scenario Overview

Imagine you’re on a work trip with your partner. You are focused on on-site work, while your partner is working remotely. Back home, she relies on an external monitor to extend her workspace. However, while traveling, she only has her laptop—limiting her to a smaller screen. Since you also have your laptop with you, the question arises: Is it possible to turn your laptop into a second monitor for hers?

Understanding the Possibility

In general, laptops are designed primarily to serve as display devices, not as secondary monitors. Most laptops do not natively accept incoming video signals to be used as external displays. Instead, they typically output their display to external monitors via HDMI, DisplayPort, or USB-C, but they do not typically accept incoming video signals by default.

Solutions and Workarounds

Fortunately, there are software-based solutions that allow a computer to act as a second monitor for another device. These solutions work over your local Wi-Fi network or via Ethernet, turning one laptop into a secondary display for another.

Here are some popular options:

1. Duet Display
2. Originally designed to turn iPads into secondary monitors, Duet Display also supports Windows and macOS laptops.
3. Requires installing the software on both devices.
4. Connects over USB or Wi-Fi.

5. Provides a relatively seamless experience with minimal lag.

6. Spacedesk

7. Free software that enables Windows PCs to extend or duplicate their display onto other devices via network.
8. Works over Wi-Fi.
9. Compatible with Windows and certain Android tablets or other Windows devices.

10. Easy to set up and reliable for daily tasks.

11. Splashtop Wired XDisplay

12. Similar to Duet, supporting USB connection.
13. Turns a device into an additional monitor.

14. Compatible with Windows and macOS clients.

15. Luna Display / Other Hardware Solutions

16. Hardware dongles designed for