Connecting 2014 iMac to 2024 Mac mini

Using the old iMac as a monitor is no longer supported. Apple killed that feature over a decade ago in hardware and almost eight years ago in macOS.

Please also see: Using an iMac As A Monitor (Thank you, John Galt)

You'll need to buy a p;roper monitor for your Mac mini to get it set up and use it.

Depending on your taste, you can find an okay monitor starting at about $150 these day.

Per the link above:

• Only certain older iMac models, introduced between 2009 and mid-2014, could be used as target displays.
• The intended target iMac must be running macOS 10.13 High Sierra or earlier; it does not work with macOS 10.14 Mojave or later, or with Boot Camp and Windows.
• In all cases the source Mac that you're connecting FROM must have been introduced in 2019 or earlier and have macOS 10.15 Catalina or earlier installed.

You would be wise to simply buy a dedicated monitor for your Mac mini.

Your iMac cannot be used. If it could, it is already twelve years old and likely nearing its end due to age. When it fails, you will have to replace it with a monitor.

When you buy a proper monitor, you can continue to use that when you next replace your Mac mini. Should you buy another similar computer at that time then you can certainly carry over your monitor to that new computer. No muss, no fuss.

If that is an iMac (Retina 5K, 27-inch, Late 2014), it never supported Target Display Mode in the first place. Target Display Mode went away when that iMac – the first 27" 5K iMac – came out.

If it is an iMac (21.5-inch, Mid 2014), it supports Target Display Mode, using Thunderbolt input, but no recent Macs, including the 2024 Mac minis, support using it as a Target Display.

There is simply no way to use the 2014 iMac as a display with the M4 MacMini.

Neither device supports such functionality between the two.

There is no adapter, software hack, or magic wands that will make it work.

Using your old 2014 iMac as a display for a new M4 Mac mini is not supported.

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

If you have or get a new Mac mini, you will need an external display.

Connect a display to Mac mini - Apple Support

Set up your Mac mini - Apple Support

Althebrush wrote:

That is what I have read. I need a cable to connect them together. Will a USB to HDMI work?

No, it will not.

• The cable shown in your picture has a USB-A plug. USB-A was never designed to carry video of any kind. Exactly what sort of device would have a cable with those two ends is unclear, but whatever it is, I doubt it would be designed to carry video for a main display from the HDMI end to the USB one.
• The iMac (21.5-inch, Mid 2014) only accepts old-style Thunderbolt video input. If Apple had not added after-the-fact restrictions on the video source, you would still need $80+ in specialized Thunderbolt hardware simply to make a Thunderbolt connection from a modem Mac to that old iMac. (A Mac with a 21.5", 1080p screen, at that.).
• Apple did add restrictions, so a new Mac mini will not support using that old iMac as a Target Display.

You need to buy a real monitor.

Please explain what you are trying to accomplish.

File Sharing? See Set up file sharing on Mac - Apple Support

Screen Sharing? See Share the screen of another Mac - Apple Support

Migration? See Transfer to a new Mac with Migration Assistant - Apple Support

Something else?

You cannot use the iMac as a display for a 2024 Mac Mini. It doesn't work that way. Target Display Mode was only available on a very few select Mac models ... over 10 years ago.

Unless you do screen sharing. But understand that screen sharing is not the same as having a directly connected display.

Althebrush wrote:

That is what I have read. I need a cable to connect them together. Will a USB to HDMI work?

https://discussions.apple.com/content/attachment/3e0a6473-6415-455b-a710-09f78d03e1ef

No. There is no way to use that iMac as a display for a new Mac mini.