Formerly known as Apple Hardware Test, Apple Diagnostics is a system-integrated feature on newer Macs running macOS Big Sur and macOS Monterey that can check your Mac for hardware issues. This article explains how to use it on Apple silicon Macs and Intel Macs.

apple diagnostics
If you think your Mac has a hardware problem, you can use Apple Diagnostics to help you determine which hardware component might be at fault. Apple Diagnostics can also suggest solutions and get you in touch with Apple Support for additional help.

Before you use Apple Diagnostics, make sure your Mac is shut down (choose Apple menu -> Shut Down from the menu bar) then disconnect all external devices except for the keyboard, mouse, display, and any Ethernet connection if you have one. Make sure your Mac is connected to a power outlet, then follow the steps below for your type of Mac.

How to Use Apple Diagnostics on an Apple silicon Mac

  1. Turn on your Mac and continue to press and hold the power button as your Mac starts up.
  2. Release the power button when you see the startup options window (you'll see the internal disk icon and a gear icon labeled Options).
    apple silicon mac startup recovery screen

  3. Press the Command-D key combination on your keyboard.

How to Use Apple Diagnostics on an Intel Mac

  1. Press the power button to turn on your Mac, then immediately press and hold the D key on your keyboard as your Mac starts up.
  2. Release the D key when you see a progress bar or you're asked to choose a language.

macos big sur apple diagnostics
After you've followed the above steps, Apple Diagnostics will begin to run on your Mac. When it's finished testing your machine, the results will be shown, including one or more reference codes to help you identify any potential issues (refer to Apple's support page to learn more about reference codes). To repeat the test, click Run the test again or press Command-R. Alternately, click Restart or Shut Down.

macos big sur apple diagnostics results no issues
To get more information about your service and support options, make sure that your Mac is connected to the internet. Then click Get started or press Command-G. Your Mac will restart and open a webpage with more information. When you're done, choose Restart or Shut Down from the Apple menu.

Popular Stories

iOS 18 Mock iPhone 16 Feature Gray

Revealed: iOS 18 Works With These iPhone Models

Monday June 10, 2024 3:57 am PDT by
iOS 18 will be compatible with the same iPhone models as iOS 17, according to a post on X today from a private account with a proven track record of sharing build numbers for upcoming iOS updates. iOS 18 will be compatible with the iPhone XR, and hence also the iPhone XS and iPhone XS Max models with the same A12 Bionic chip, but older iPhone models will miss out. Here is the full...
ios 18 tile summary

Apple Announces iOS 18 With New Customization Features, Redesigned Photos App, and More

Monday June 10, 2024 10:17 am PDT by
Apple today previewed iOS 18, the next major update to the operating system for the iPhone, with new customization features, a redesigned Photos app, and more. iOS 18 features new customization tools for the Home Screen. App icons now feature Dark Mode and users can tint them with a color to create a unique look. Apps can also now be placed anywhere on the Home Screen freely. The Control...
WWDC24 Live Coverage Article

WWDC 2024 Apple Event Live Keynote Coverage: iOS 18, Apple's AI Push, and More

Monday June 10, 2024 9:20 am PDT by
Apple's Worldwide Developers Conference (WWDC) starts today with the traditional keynote kicking things off at 10:00 a.m. Pacific Time. MacRumors is on hand for the event and we'll be sharing details and our thoughts throughout the day. We're expecting to see a number of software-related announcements with a focus on Apple's efforts to infuse AI throughout its operating systems and apps....
iOS 18 Siri Integrated Feature

Massive iPhone Upgrade Coming This Week But These Devices Will Miss Out

Sunday June 9, 2024 1:25 pm PDT by
Apple is planning a major AI overhaul in iOS 18, with a feature set it is referring to as "Apple Intelligence." However, these new features will not work on older iPhones, even if they do appear on the new operating system's device compatibility list. Apple's initial AI roadmap for iOS 18 is said to come in two parts: Basic AI features that will be processed on-device, and more advanced...
m3 macbook air purple

Amazon Introduces Record Low Prices on Every M3 MacBook Air

Sunday June 9, 2024 7:57 am PDT by
On Friday we tracked new all-time low prices on the 13-inch M3 MacBook Air, and today Amazon has expanded this sale with record low prices on the 15-inch models as well. Thanks to these additional deals, every single model of the M3 MacBook Air is now available at an all-time low price. Note: MacRumors is an affiliate partner with Amazon. When you click a link and make a purchase, we may...
Next Gen CarPlay WWDC24 1

Apple Provides Updated Look at Next-Generation CarPlay at WWDC 2024

Monday June 10, 2024 7:11 pm PDT by
Apple today shared a few WWDC 2024 coding sessions related to its upcoming next-generation CarPlay system ahead of its launch later this year. The sessions include lots of updated next-generation CarPlay images, with one revealing new Vehicle, Media, and Climate apps in action for the first time. MacRumors previously discovered evidence of these apps in the iOS 17.4 beta. Next-generation...