Can't mirror MacBook Pro display to iMac

Question

Can't mirror MacBook Pro display to iMac

I've been trying to use my older (2017) iMac as an external display for my MacBook Pro M1 (2021), but to no avail (nothing shows up under the Screen Mirroring dropdown, see screenshot). I've tried through AirPlay and using a thunderbolt cable, and neither work. Ironically (and frustratingly), I can mirror the iMac's screen to the MacBook, but not the other way around (so I know they can see each other on the network). I've checked all the system settings related to displays, and they're all set correctly. Any help would be so very much appreciated.

[Edited by Moderator]

MacBook Pro 16″, macOS 15.5

Posted on Jul 21, 2025 10:42 AM

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Answer 1

Top-ranking reply

Grant Bennet-Alder

Level 10

143,413 points

Jul 21, 2025 2:35 PM in response to senselessthings

You CAN'T use your iMac as a separate display for another modern computer -- that feature has been deprecated:

Use your iMac as a display with target display mode - Apple Support

Read very carefully. Only for certain Macs, and only for MUCH older MacOS.

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Answer 2

Jul 21, 2025 3:49 PM in response to senselessthings

Apple got rid of Target Display Mode when the first 27" 5K Retina iMac came out in Late 2014. Your 2017 iMac does not have it, and therefore cannot act as a cabled monitor even for other older Macs. See the Support article that Mr. Bennet-Alder mentioned.

The reason you don't see the option to do Screen Mirroring to your 2017 iMac is that the iMac is too old to act as an AirPlay Receiver for AirPlay to Mac. AirPlay from Macs to Apple TV set-top boxes has been around for a long time – and your 16" MacBook Pro is new enough to support being an AirPlay Receiver – which explains why that 2017 iMac can do AirPlay mirroring to the MBP (but not vice versa).

See: Continuity features and requirements for Apple devices - Apple Support

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