Apple's own solution, Sidecar, is Mac-only — there is no equivalent Apple feature for Windows, and none has been announced.
For a Windows PC the route is third-party software. The main options, all current in 2026: Duet Display (paid), spacedesk (free), Splashtop Wired XDisplay (paid, USB-only), and Luna Display (hardware dongle, no subscription).
What to compare: latency (wired USB is consistently lower than Wi-Fi; for anything interactive, prefer wired or a 5 GHz network), input support (touch and Apple Pencil work on some, not all), and OS support — most work on Windows 10/11 with modest GPU requirements, but check the vendor's compatibility matrix for your exact setup.
As a general rule, for everyday office work these apps are workable, while a dedicated portable monitor is usually sharper, simpler and adds no latency of its own. The iPad-as-display route shines when you already own the iPad and only need a second screen occasionally.
Sources: https://support.apple.com/102597
— Osnivo Editorial