I have a mid 2011 imac 21.5 inch(running high sierra) and a Macbook pro 15 inch mid 2015(running big sur). I want to use my imac as a monitor, I have the thunderbolt 2 cable and it doesn't seem to work.
Thanks
MacBook Pro
The 2015 MacBook Pro must be running Catalina or earlier.
Carefully follow the directions @ > Use your iMac as a display with target display mode - Apple Support
Does this line means that my 2015 mbp can be used ?
Yes a 2015 MacBook Pro can use the 2011 iMac, but it must be running Catalina or earlier.
Problem is, your MacBook Pro is running the later Big Sur which does not support TDM.
Ohhh thanks
You're welcome.
Since downgrading the macOS is generally not a good idea or option, I suggest just getting and using an aftermarket display to use with the MacBook Pro.
using my imac as monitor for my macbook pro
