Using a Mac as an External Display for Another Mac

This is a first pass at trying to come up with a general solution to using a Mac as an external display for another Mac. The idea is to reuse old equipment or supporting more monitors than a Mac directly supports.
My tests show that older Macs can be used as displays for Macs running Big Sur or Monterey. I have further testing to see if it works on older operating systems like Catalina, Mojave and High Sierra.
You can do this using AirPlay if your systems are running Monterey but many would like to use older, and sometimes much older systems as displays for newer systems.
Sorry for the video quality - this is the first time I've done a video using a camera in a couple of years and it took me a while to find a usable mount. The video overall took about 7 hours as I had to install El Capitan on the old MacBook Pro and do multiple takes. At least I learned a lot about doing videos with cameras.

[thekakashi]

Saved me a lot, i was about to buy duet display, i don't need it anymore, using my hackintosh desktop and my macbook pro 2009 like a second screen, thank you so much

[Andysyoutubemess]

Thanks - this works better than the built-in airplay sharing between my two 5k iMacs (2020 and 2014, both on Ventura). A lot crisper on the 2560x1440 HiDPI setting - despite the same settings on both systems 🤷‍♂ I couldn't have managed it without your video, and suspect I'll need to refer back for a few times before I work it out myself!

[yeahshegamesfairy]

Omg ty I couldn't see what you were doing but when I reminded and listened, it worked!!!

[BackToFE_OnlyTruth]

Thanks Micheal. There is a missing part in this video. what exactly is a "virtual display"?
There is an icon added in the upper bar, you click it and then you get a menu. What is that menu Micheal? and where can I find it? The resolution is very low and we can't read what's written there. I would love it if you reavel the mystery :) tnx again

[Gerald_G]

Forgive my ignorance, but I have not been able to find how to do that first step of creating a virtual display.

[sarsoorGio]

how did you create the virtual display / change the resolution so they match? I am not even seeing the two monitors in display settings so I am getting stuck early in this process. TY.

[rchrd_dnb]

Thank you so much, Michael! This is a great solution!

[AccidentalBiker]

Thanks for the video. Got a quick question pls. If you plug an external monitor to your old Mac, can you share the screen from your new Mac to old Mac external monitor?

[eliavanmechelen]

Can you please explain to me how you create the virtual display. I can't clearly see the menu bar item. Thanks!

[gerotone]

Hello Michael, is this method working with Sonoma? Somehow these steps don't work with the current OS

[laureng.g.]

Hi Michael. Thank you for this video. I am planning on upgrading from a Macbook pro 2015 to a Macbook Pro M2. Curious if this works for these models?

[HuntingForJaws]

hey I was wondering if you knew if there was a cord I could use to do this, I wanna run my MacBook Air (2017) off my new m3 mac as a secondary monitor but use the m3 as the powerhouse for both screens, any info would be greatly appreciated, thanks for the video

[EnriqueAviles]

Hi, has anybody found a solution for when using Sonoma? I don't get the virtual monitor in neither my Macbboks (intel nor M1)

[movdqa]

I've tested this on a 2007 MacBook Pro, 2021 MacBook Pro, 2010 iMac 27, 2014 iMac 27, M1 mini, M1 Studio, and 2015 MacBook Pro 15. I have not tested it on a MacBook Air but I have no reason to think that it woudn't work.

[jauharulazkiya]

Hi Michael! I'm using MacBook Pro M1 with Ventura OS and M2 with Sonoma OS, I can barely connect a both of them in display settings, but it can only mirror the display, I can't extended it. Could you help me please?

[AudioRev-fz]

Can I do this on two MBA M2? Do I still need that virtual screen?

[FRANCESCO-blmq]

I need help, I have a MacBookPro18.4 and I would like to use my old MacBook Pro Mid 2014 as an extension screen, I work with photo editing programs, so I want a fairly fast sharing, I would like to know what I need to make the system work All .

[annetermull]

Hey, So I managed to share my screen with my other MacBook. But It is really like sharing my screen. Not as you have in your video a second extended monitor screen. If I drop down a menu in on one computer it does the same at the screen on the other computer. So I can't use it as a extra mojito. Any idea how to fix this?

[MichaelBouhnikProductions]

Hi Michael, i just bought the new macbook pro m2, could i use my 2017 macbook pro as my secondary display? ( i even have an old 2011 17inch macbook pro available for external display)
could i use any of the old macbooks as secondary display?

[paige.campbell]

Hi Michael! I'm using a 2014 MBP (Big Sur) as the extended monitor for my 2019 MBP running Ventura. Is there a way to connect the two via Better Display only, or does it require this 'screen share' access shown in this video? I was able to get it to work only once using this screen share OS option, but the lag is so much it's not helpful for my video editing needs (FXP). Have been reading the forums etc to no avail. Thanks!