Macbook Pro (M1) can't extend screen to iMac 27 (2017)

Hi folks: this is driving me crazy. I have a 2017 iMac 27 running Ventura 13.74. I also have a MacBook Pro M1 running Sonoma.

I want to be able to extend the MacBook's display to the iMac so I can use it as a very nice monitor. However I can't get the MacBook to recognize the iMac. If I select the "+" in the Display menu, it doesn't show up.

Tried:

holding down "Option" key.

rebooting all devices

different cables (Thunderbolt 4, USB C, etc)

Nothing seems to work. I also have another Macbook Air and 27 iMac (2019) both on Sonoma, and have no problem extending the screen, so I don't think I'm missing a step.

Is this some hardware/software incompatibility? Thanks

iMac 27″, macOS 15.3

Posted on Feb 16, 2025 6:34 AM

Top-ranking reply

D.I. Johnson

Level 8

35,567 points

Posted on Feb 16, 2025 9:33 AM

AirPlay to Mac and Continuity features require a 2019 iMac or newer.

Continuity features and requirements for Apple devices - Apple Support

Also, target display mode - an old feature that enable iMacs to be used as displays - is dead for some years now. Dead since 2014 in hardware and dead in software since Big Sur was released.

View in context

Macbook Pro (M1) can't extend screen to iMac 27 (2017)

Similar questions