Is it safe to unplug an iMac every day?

As long as you shut it down first, then no, there's normally no problem, assuming of course you don't cause mechanical damage when disconnecting, reconnecting or moving it. There is always a very small chance of the power surge that occurs when reconnecting any electronic device to AC causing damage. The chance is, as I said, small, though.

You might want to consider trading in your iMac toward a MacBook, though, if you really need to move it multiple times a week.

Regards.

Make sure you shut it down first. Doesn't hurt anything.

There is always a moment (on the order of milliseconds) of sudden power when you plug in a device (the device is going from zero voltage and current to some higher level), and that can on rare occasions cause damage. I've seen it happen on more than one occasion. So when some asks "is it safe", I caveat my response with that caution. This is particularly true when one is talking about a device that takes AC power directly, as is the case with an iMac, rather than being mediated through an external power supply that cuts the voltage and current down.

Regards.

In addition to what the others have shared, it is also a good idea to turn off "Start up automatically after a power failure" in the Energy Saver Settings, so that the iMac doesn't startup when it is first plugged back in.

varjak paw wrote:

There is always a moment (on the order of milliseconds) of sudden power when you plug in a device (the device is going from zero voltage and current to some higher level), and that can on rare occasions cause damage.

Of course when you plug something in it will have "sudden power" when it had none. That is not my understanding of a power surge. Maybe I've just been lucky but I've been plugging devices in my entire life and never experienced that. I don't know anyone that has.

As I said, I have seen this on more than one occasion over the years. It's not common, but it does happen, and the more often someone disconnects and reconnects power, particularly to AC-level voltage and current, the larger the chance that some problem will occur. As to what "power surge" means, let's not get into semantics. Any sudden increase in power can cause circuitry to fail.

Regards.

varjak paw wrote:

There is always a very small chance of the power surge that occurs when reconnecting any electronic device to AC causing damage.

You may want to read the definition of "power surge"

FWIW, I've never heard of a power surge occurring simply by plugging in a electrical device.

I have a very different take on this.

Your 2019 iMac has a coin-type internal backup battery, sometimes called the PRAM battery. Its purpose is to preserve things such as startup disk and settings should the computer be removed from wall power temporarily for moving or service.

When the computer is connected to wall power, there is a bypass circuit the diverts a tiny "trickle" current around the power supply to maintain settings; the battery does not have to work unless power is disconnected.

Unplugging every day will cause the life expectancy of the PRAM battery to drop from years to months. If it dies, you have to reestablish the setting every restart. I had this happen to a company Mac that I turned off at its battery backup every night— same as unplugging AND recommended by one of the Windows-leaning company IT techs.. After a few months, the computer started showing odd symptoms including not knowing where its startup disk was. A new PRAM battery and not cutting power any more fixed that.

Here's the rub: to replace the $2 battery in a 2019 iMac requires a significant teardown of a computer Apple did not design to be opened by us mere mortals. It's sealed. A popular self-service site show 62 steps 😳 to simply access the PRAM battery, and more to reassemble.

A local service provider owner told me it takes his crews two hours to open, service, repair, and reseal a 2012-2019 iMac. He added that tech labor costs in the US Inland Northwest are US$65-80 per hour. That is up to $160 plus the cost of the reseal kit to have an iMac PRAM battery replaced. That turns unplugging to be "green" to save a few cents a week into a very expensive gesture.

There was a time when we could quickly remove and replace a PRAM battery from most Macs without tools. We took advantage when storing our Macs. If it was for more than a few days, we pulled the PRAM batts and taped them on the inside of the case. Easily-accessible iMac PRAM batteries are long gone, sacrificed before the Altar of Minimalist Design.

We turn off our iMacs while traveling but never unplug them for more than a few hours at a time. Anything more is pushing the PRAM battery beyond its intended purpose.