Beyond Display · old iMac guide

Use an old iMac as a second monitor for another Mac.

Beyond Display is a free Mac-to-Mac extended display app. If your old iMac can run macOS 12.3 or later, it can become extra desktop space for a MacBook, Mac mini, Mac Studio, or another Mac.

Can an old iMac become a second monitor?

Yes, when the iMac is still compatible with macOS 12.3 or later. Install Beyond Display on both Macs, connect them locally, and use the iMac as an extended second monitor instead of buying another external display.

This is different from Apple Target Display Mode. Beyond Display does not unlock unsupported legacy iMac hardware, and it does not turn every old iMac into a monitor. It works when the iMac can still run the required macOS version.

Free old iMac second monitor setup

FeatureFreeBeyond Display can be used without a paid plan, subscription, or product account.

FeatureNo login requiredThe two Macs do not need to share an Apple ID, internet account, or cloud sign-in.

FeatureWired or wirelessUse the same Wi-Fi network, Ethernet, or a direct Thunderbolt connection with Thunderbolt Bridge.

How to use an old iMac as a second monitor

Step 1Check the old iMacThe iMac must be able to run macOS 12.3 or later. Very old iMac models that cannot run macOS 12.3 are not supported.

Step 2Install Beyond Display on both MacsInstall the same app on the primary Mac and on the iMac you want to use as the second monitor.

Step 3Start an extended display sessionChoose the old iMac from the primary Mac, then use it as extra desktop space for documents, reference pages, chats, or videos.

Old iMac second monitor FAQ

Can I use an old iMac as a second monitor for another Mac?

Yes, if the old iMac can run macOS 12.3 or later. Beyond Display uses another compatible Mac as an extended display for your primary Mac.

Is Beyond Display free?

Yes. Beyond Display is free to use and does not require a paid plan, subscription, or login.

Can I use an old iMac as a second monitor for a MacBook?

Yes. A compatible iMac can become extra desktop space for a MacBook when both Macs run macOS 12.3 or later.

Can the connection be wired or wireless?

Yes. Beyond Display can use Wi-Fi, Ethernet, or a direct Thunderbolt connection between the two Macs.

Beyond Display links

ProductBeyond Display product pageSee the full product overview for using another Mac as a second monitor.FAQBeyond Display FAQRead short answers about requirements, setup, connection options, and downloads.DownloadDownload Beyond Display 1.2Download the current DMG release for macOS 12.3 or later.