Mac

Mac kernel panic and unexpected restart

A kernel panic is macOS's version of a crash screen, telling you it hit a serious problem it couldn't recover from; it's often caused by a bad driver, faulty RAM, or an incompatible external device.

Difficulty
Moderate
Time
30–60 minutes
DIY cost
$0
Pro cost
$100–$250

Symptoms

  • Screen goes gray/dark with a message saying the computer restarted because of a problem
  • Mac restarts suddenly without warning
  • Panics happen more often under heavy use or with a specific accessory connected
  • A notification appears afterward reporting the restart

Likely causes

  • CommonA third-party kernel extension or driver conflicting with macOSOlder or poorly maintained drivers are a frequent cause of kernel panics.
  • CommonA problematic external device or peripheralFaulty USB devices, docks, or external drives can trigger a panic.
  • PossibleFaulty or incompatible RAM (on Macs with user-upgradeable memory)Bad memory can cause instability serious enough to crash the kernel.
  • PossibleA macOS bug triggered by a specific app or updateSome panics are software bugs that get fixed in later updates.
  • Less commonFailing storage or logic board hardwareThis is less common but should be considered if panics are frequent and unexplained.

What to do

  1. Note what you were doing and what was connected right before the panic, since this often points to the cause.
  2. Disconnect all non-essential external devices (drives, docks, hubs) and see if panics stop.
  3. Check for macOS updates in System Settings > General > Software Update and install any available.
  4. Update or remove any recently installed third-party software that adds system-level extensions (some security, virtualization, or driver-related apps do this).
  5. If you added RAM yourself, reseat it or test with the original RAM to rule out a bad module.
  6. Check Console (Applications > Utilities) for the panic log to see which process or driver is referenced.
  7. Run Apple Diagnostics (restart while holding D on Intel Macs, or via the recovery options on Apple silicon) to test for hardware faults.
  8. If panics continue after removing recent software/hardware additions, back up your data and consider a clean macOS reinstall.

Tools and parts

  • None required

When to call a pro

If Apple Diagnostics reports a hardware fault, or panics continue after software troubleshooting, an Apple Store or authorized repair shop can perform deeper hardware testing.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.