macOS Won't Boot — Stuck on Apple Logo or Loading Bar Fix

What Does This Error Mean?

When your Mac gets stuck on the Apple logo or the loading progress bar at startup, macOS is failing to load. This can happen after a failed update, a corrupted system file, or a failing drive. Most cases are fixable using Recovery Mode without losing your files.

Affected Models

MacBook Air
MacBook Pro
iMac
Mac Mini
Mac Pro
Mac Studio

Common Causes

A macOS update failed partway through, leaving the system in a broken state
A third-party system extension or kernel extension is preventing startup
The internal drive has file system errors preventing macOS from loading
A peripheral device connected to your Mac is causing a startup conflict
The macOS system files have been corrupted or accidentally deleted

How to Fix It

Disconnect all external devices. Unplug every USB device, hub, and monitor except power. Then restart your Mac. A faulty peripheral can prevent startup.

This is the simplest fix. Try it first before anything else.
Try Safe Mode. On Intel Macs: hold Shift at startup. On Apple Silicon Macs: hold Power until startup options appear, select your disk, then hold Shift and click Continue in Safe Mode.

Safe Mode loads macOS with only essential components. If it boots in Safe Mode, a third-party extension is the likely cause.
Boot into Recovery Mode. On Intel Macs: hold Command + R at startup. On Apple Silicon Macs: hold the Power button until startup options appear, then click Options.

Recovery Mode lets you run Disk Utility, reinstall macOS, or restore from a Time Machine backup — all without needing macOS to fully boot.
Run First Aid in Recovery Mode. Once in Recovery Mode, open Disk Utility, select your main drive (usually Macintosh HD), and click First Aid.

File system errors can prevent macOS from booting. First Aid repairs these errors and often gets the Mac booting again.
Reinstall macOS from Recovery Mode. If First Aid does not help, choose Reinstall macOS from the Recovery Mode menu. This reinstalls macOS without deleting your personal files.

A macOS reinstall over an existing installation replaces system files without touching your documents, photos, or apps.

When to Call a Professional

If your Mac does not boot into Recovery Mode and Apple Diagnostics also fails, the hardware may have failed. Visit an Apple Store or authorized repair shop for diagnosis. If your drive has failed and you have no backup, a data recovery specialist may be able to recover your files.

Frequently Asked Questions

Will reinstalling macOS delete my files?

No — reinstalling macOS through Recovery Mode replaces only the macOS system files. Your documents, photos, music, and apps are not deleted. However, it is always a good idea to have a recent Time Machine backup before doing any major repair.

My Mac shows a circle with a line through it at startup. What does that mean?

A circle with a slash (the 'no entry' sign) means macOS cannot find a valid startup disk, or the startup disk is damaged. This is more serious than a stuck loading bar. Boot into Recovery Mode and run Disk Utility First Aid first.

How do I start Recovery Mode on an Apple Silicon Mac (M1, M2, M3)?

Press and hold the power button — do not tap it, hold it down. Keep holding until you see the 'Loading startup options' screen. Click Options, then click Continue. This opens Recovery Mode on all Apple Silicon Macs.