Using iMac 2011 as a second monitor for Mac Mini M4

The 2011 iMac supports Target Display Mode.

But Apple added restrictions on the video source. The M4 Mac mini is too recent to support using any iMac, even a 2011 iMac, as a Target Display.

The 2011 iMac has Thunderbolt and therefore only supports Target Display Mode using Thunderbolt input. Since Thunderbolt changed connectors between Thunderbolt 2 and Thunderbolt 3, you would need $80 in specialized Thunderbolt connection hardware ($50 Apple Thunderbolt 3-to-2 adapter + $30 Thunderbolt 1/2 cable) to hook up the M4 Mac mini and the 2011 iMac using Thunderbolt. Then you would learn that although you had satisfied the requirement to make a Thunderbolt connection, the M4 Mac mini was still too recent to support using the old iMac as a display.

Read the bad mews here: Use your iMac as a display with target display mode - Apple Support

you can do it using software but mind you the imac will be using ALOT! more electricity than a normal monitor

Use iMac as monitor: 5 Solutions - 9to5Mac

and the performance will not be like a normal cable connected monitor so I would not advice it for gaming or video

well as a rule of thumb then no computer by default that have a connector to a monitor use it as input but only as output as in the computer connecting to another monitor. that is how it's always been, it was the special case when apple had their target display feature many years ago which is no longer a thing

Techno-boob wrote:

[...] Wondering if it's better to go and buy a second Dell monitor rather than paying for additional software, which may or may not give me the experience I'm looking for.

Absolutely! 👍🏽

Yes. Aesthetics in the workspace is often underrated. 🙂