Converting your laptop into a second monitor is simpler than it seems but requires more than just an HDMI cable. For Windows users with Windows 10 or 11, the built-in Miracast wireless casting feature allows mirroring or extending the display via Wi-Fi. Simply go to Settings > System > Projecting to this PC, enable Wireless Display, and pair devices.
On Mac, Air Play (available on Macs from 2018 or later) connects laptops wirelessly through the Air Play Receiver and Displays settings. For wired connections with lower latency, Deskreen is a free open-source tool that works across different operating systems over Wi-Fi. The method requires both devices on the same network and, for wireless setups, active Wi-Fi.
These solutions let you extend desktop real estate for more tabs and multitasking without buying expensive hardware.
Source: Engadget · Summarized by HeadlinesBriefing