The best Remote Desktop alternative to Spacedesk is Multiplicity. It's not free, so if you're looking for a free alternative, you could try Weylus or DFMirage. If that doesn't suit you, our users have ranked more than 25 alternatives to Spacedesk and four of them are Remote Desktop Tools so hopefully you can find a suitable replacement.
Multiplicity offers a virtual KVM solution, managing several computers with one keyboard and mouse. Its remote modes enable cursor transition across monitors and centralized control. Users can transfer files, stream audio, and lock computers without extra hardware, suitable for command rooms, IT desks, and home users.
Turns iOS or Android devices into efficient second displays or graphics tablets for Mac and PC, delivering zero-lag, high-resolution output with touch, gesture, and touch bar support, hardware-free setup, secure remote desktop capabilities, and end-to-end encryption.
Weylus turns your tablet or smart phone into a graphic tablet/touch screen for your computer.
I like this software. It's lightweight and easy. I try my smartphone and it worked
DFMirage is "cutting edge" video driver mirroring technology for the Windows. It is a driver for virtual video device managed at DDML level of the graphics system that exactly mirrors the drawing operations of one or more physical display devices.
United States
Multiplicity make it possible to use your mouse and keyboard for 2 pc while Spacedesk make a laptop etc. an additional screen for your desktop.