mac Mini and older iMac compatability

2011 iMacs support Target Display Mode, using Thunderbolt input, but Apple added restrictions on Target Display Mode. No current Macs support using any iMac as a Target Display.

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

Even if Apple had not added the restrictions, you would need $80+ in specialized Thunderbolt gear (a $50 Apple Thunderbolt 3-to-2 adapter + a $30+ Thunderbolt 1/2 cable) to use the old iMac as a Target Display. Once iMacs got Thunderbolt, Target Display Mode required Thunderbolt input. It was only the 24" and 27" iMacs from 2009 and 2010 that could accept regular DisplayPort input.

Based on your tag line, it appears that you have a 21.5" iMac with a 1920x1080 pixel display. These days, you can buy

• 24" 1920x1080 pixel displays with poor color accuracy for about $80
• 24" 1920x1080 pixel displays with IPS panels and 100% or near-100% coverage of sRGB for about $150
• 27" 3840x2160 pixel displays with IPS panels and 100% or near-100% coverage of sRGB for as little as $300 to $350.

So even if there weren't restrictions on the video source, the cost of making the connection, versus the value, and age, of that old display, would argue for buying a real standalone monitor.

As you've already been appraised the Mac Mini is too new for Target Display Mode. You'll have to get a 3rd party monitor. They can be had for anywhere from $100 to $350 depending on what you want in a monitor. I get a 32" LG 4K monitor for $331. The entire outfit, a Mini M4 with 16 GB of RAM, a 1 TB SSD and the 32" 4K monitor w/speakers was only $1417 whereas a comparable configured 24" iMac was $650 more.

Just concentrate on the monitor that will server you best.

No. you cannot use Target Display Mode (using the old iMac) for a display for a new MM. Please refer to Target Display Mode for Apple's information about Target Display Mode.

You need to buy external display to go along with the MM, you can find them beginning below $100 or you can spend as much as $1500 for one, however for about $300 you can get an excellent external display. Buy one with HDMI and ensure you get an excellent quality HDMI cable to connect it with.

To migrate from the old iMac to the new machine simply follow the steps in Setup Assistant and Migration Assistant for an easy, fast and reliable migration. When buying the new MM DO NOT scrimp on internal storage, if the old iMac has a 1 TB HD, get a MM with a 1 TB SSD otherwise your migration could be a nightmare!!!!

The ability to use an iMac as a display is on longer an option. You will have to buy an external monitor. For once, the salesman at the store is correct.

Nope, you will need an external display for the Mac mini.

see > Connect a display to Mac mini - Apple Support

Not possible, unfortunately. Use with a regular/4K HDMI display.

As for what displays you can use with a M4 Mac mini or M4 Pro Mac mini, here are Apple's Technical Specifications.

Mac mini (2024) - Tech Specs - Apple Support

Connect a display to Mac mini - Apple Support

Both versions of the Mac mini

• Have a HDMI port
• Have three rear-panel USB-C ports that support DisplayPort and Thunderbolt (among other things)
• Can drive up to three displays (see details in linked articles)

Most modern third-party displays provide video inputs using some combination of DisplayPort, HDMI, and USB-C. There are a few monitors – mostly 5K and 6K monitors – that want Thunderbolt input. You can get adapters to go from USB-C (DisplayPort) to just about anything: DisplayPort, HDMI, single-link DVI, dual-link DVI, even VGA. So often you'll have multiple choices of how to connect a M4 or M4 Pro Mac mini to a particular monitor.