You recognize most of the processes you see while browsing Activity Monitor, but not hidd. The name is cryptic, and there's no icon for you to recognize. Should you be worried?
This article is part of our ongoing series explaining various processes found in Activity Monitor, like kernel_task, mdsworker, installd, and many others. Don’t know what those services are? Better start reading!
The hidd process is not harmful, and is actually part of macOS itself. The cryptic name stands for Human Interface Device Daemon. This daemon interprets all of your mouse movements and keyboard taps, meaning it's essential if you want to use your Mac. Other input devices, such as tablets for drawing and game controllers, are also managed by this daemon.
It's rare for hidd to cause problems, but it's always possible. Here's what to do if that happens.
What to Do if hidd Is Using Excessive System Resources
It's rare, but occasionally Mac users report that hidd is using an excessive amount of CPU or Memory. In most cases simply restarting your computer will solve the issue. It's also possible to kill hidd directly using Activity Monitor. You'll briefly be unable to use your mouse and keyboard if you do that, but macOS will re-launch the daemon shortly after and everything should be back to normal.
If high resource usage persists, the likely culprit is third party software. If you've recently installed drivers for a third party input device, or software that lets you do things like customize your key bindings, this could hypothetically be the issue. Try uninstalling this software, then see if that solves the issue.
hidd Will Keep Your Mac Awake
If you're trying figure out what's keeping your Mac from sleeping, you'll find hidd listed as a reason why. There's a good reason for this: hidd handles mouse and keyboard input, and you used your mouse and/or keyboard to run the command. You don't want your computer to fall asleep while you're using it, so hidd prevents your Mac from falling asleep so long as you're typing or moving your mouse.
Basically the act of observing changed the results, a problem you share with many a physicist. Whatever's keeping your Mac awake, it's probably not hidd, so move on to the next thing.
Photo Credits: gesche4mac, Dondre Green