Keyboard options for 2011 iMac

If you are considering an Apple keyboard, check its system requirements carefully. Apple has a very bad habit of raising the minimum system requirement each time they release a new round of Magic Keyboards or Magic Mice.

None of the Magic Keyboards with Touch ID sensors are officially compatible with your Mac. Apple says that they are for Macs with Apple Silicon processors. The Magic Keyboard (USB-C) requires macOS 15.1 (Catalina) or later. So also excludes your Mac.

The Magic Keyboard with Numeric Keypad is old enough that it has a Lightning recharging port. It "only" requires macOS 10.12.4 (Sierra) or later, so would work with your Mac. (Unless for some reason you ever had to wipe your Mac, reinstall the original OS, and work your way up - then you might need to temporarily borrow a more generic USB keyboard.)

Magic Keyboard with Numeric Keypad for Mac models - Apple

Pretty much any USB-A Mac or USB-A PC keyboard will work.

I’d avoid USB-C keyboards (and USB-C with Bluetooth) here, as you’ll need a dongle to connect those to USB-A, and I’ve had mixed success with keyboard dongles over the years.

We had no issues using the Logitech MK120 Combos with old Mac's.

logitech MK120 combo

Hi there,

Please search for the Magic Keyboard 1st generation.

Be sure that any keyboard you purchase will work with current Macs as your Mac is ancient is computer years (almost as old as me in people years) and is considered obsolete by Apple. That means they won't fix any issue with it nor are parts still readily available.

It it's working and does what you need then get a reasonable quality keyboard and carry on.

What about them?

Writing an effective Apple Support Communities question - Apple Community