What is “Safe Mode” and How Does That Help Me Anyway? :: My First Mac - Help Buying and Getting Started with Your New Mac

What is “Safe Mode” and How Does That Help Me Anyway?

Quick Scan

Safe Mode is a start up sequence that only uses the basics of OS X

Hold down the Shift key when starting up your Mac for Safe Mode.

Use Safe Mode to continue trouble shooting your Mac.

Oh-No, My Mac Won’t Start. Now What!?

6 Steps to Solve Your Mac Problem

What to Do When Your Mac Crashes

Finding Help on Apple’s Website

Top 5 Tips for Getting Help from the Genius Bar

2 Ways Time Machine Saved My Mac

Helpful Mac Sites on the Internet

What is "Safe Mode" and How Does That Help Me Anyway?

By: Chris Kerins
Categories: Getting Help

Yes, Macs crash. Yes, they can get fouled up by misbehaving software. No, it's not a virus. It's just that computers (including Macs) are not 100% reliable. Sometimes a component fails. Sometimes software isn't working the way it was meant to. Hopefully it doesn't happen so often that it sours your experience.

But what do you do when your Mac keeps crashing or not starting up all the way? One way to help trouble shoot your Mac is by starting up in Safe Mode.

Safe Mode is a start up sequence that tests your hard drive and shuts down unnecessary parts of Mac OS X so that you at least get the basics going. This is what Apple says is involved:

It forces a directory check of the startup volume.

It loads only required kernel extensions (some of the items in /System/Library/Extensions).

In Mac OS X 10.3.9 or earlier, it runs only Apple-installed startup items (some of the items in /Library/StartupItems and /System/Library/StartupItems - and different than login items).

Mac OS X 10.4 Tiger only: It disables all fonts other than those in /System/Library/Fonts .

Mac OS X 10.4 Tiger only: It moves to the Trash all font caches normally stored in /Library/Caches/com.apple.ATS/(uid)/ , where (uid) is a user ID number such as 501.

Mac OS X 10.4 Tiger only: It disables all startup items and any Login Items.

I'm guessing that "Tiger only" means Tiger and Leopard.

What that means is that you should be able to start your Mac and make some trouble shooting adjustments to see what is causing you problems. Some things won't work, like WiFi (See Dig Deeper for a work around) and some video like DVD player and parts of iMovie.

So how do you start up in Safe Mode?

Be sure the computer is shut down. Press and hold the power button if necessary.
Press the power button.
Immediately after you hear the startup tone, press and hold the Shift key.
Tip: The Shift key should be held as soon as possible after the startup tone but not before.
Release the Shift key when you see the gray Apple and progress indicator (looks like a spinning gear).

Why would you use Safe Mode?
Use Safe Mode when you are trying to figure out why your Mac is giving you trouble. Maybe it keeps crashing or freezing, even after restarting. Maybe you just need to get into your files and get them to another Mac to keep working. Safe Mode should let you access you Mac in most situations to make adjustments or copy files.

I've never had to use Safe Mode on my 5 OS X Macs over the years, but recently my buddy ran into trouble with the screen freezing after start up. We couldn't sort out what was wrong using Safe Mode, but at least we could back things up and then did and Archive and Install from the install disc. Now his Mac is doing just fine.

Safe Mode won't solve your problems, but it should help you down the road to solving your problem.

Have you had to use Safe Mode? Did it work? What tips do you have to share? Let us know in the Comments section below!

DIG DEEPER

What is Safe Boot, Safe Mode? (Mac OS X) - Apple

Mac OS X: Starting up in Safe Mode - Apple

Use wireless networking in safe boot mode


	This button is an easy way to let readers bookmark articles on Digg, Del.icio.us, Stumbleupon, Google Bookmarks and other services with a single click. You can find out more about Social Bookmarking here.

What is this?

Tell A Friend

Print Page

Your Comments:

All time when my Mac is slowwing or strange, I use Safe Mode but whith a little utility called Applejack. "Little" but great. All time I use Applejack mi Mac return to running well.

Jacques
10/10/2008 at 09:31 PM

mine willna start up in safe at all! Ugggg!

mommy of 4
10/12/2008 at 02:46 PM

Safe mode is required when you have to fix a problem such as virus infection or uninstalling safe]http://dadecoders.blogspot.com/2008/05/add-safe-mode-in-boot-list.html"]safe mode[/url] and if not timed properly you will need to restart windows xp again.

Afrer Add safe mode to your boot list restart your machine and you will see another label as “XP- Safe Mode” added to the list.PS: This option is also used for adding any other windows installation on other partition.------

dadecoders
11/09/2008 at 04:20 AM

Applejack is great for fixing small problems. I run it monthly to keep my MacBook Pro running smoothly.

Ted Lamb
01/13/2009 at 01:23 PM

Tried several times. Just hangs displaying the spinning gear!

Brad
08/02/2009 at 12:10 PM

re: Shift key should be held as soon as possible after the startup tone but not before.

But what if you have the sound turned off or it's not working and there's no startup tone. Then How do you know when to press the shift key for safe mode?

And what happens if you do begin to hold it down immediately after reboot? what are the consequences of doing that? (this is on a mac, not windoze btw)

I am trying to troubleshoot why the cpu temp, fans go so high w/ regular boot, but browsers are faster, not as high cpu/temps/fans when starting from safe boot.

I mean, how do you actually figure out what the problem is?

I really would appreciate the help.

(using 10.4.11 on a G5 ppc imac btw; yes it's no longer the bright new thing, but then again, neither am I! and as a non-tech non-expert, I kinda need specifics and step-by-step help in this stuff). so if you can help or point me in the right direction...?

surely would appreciate it. thanks & cheers!

Jerry
04/11/2011 at 11:36 AM

I wasn't really having any problems with my Macbook Pro other than it slowly seemed to be getting slower. I had heard that starting it up in Safe Mode eliminates some unnecessary files that can bog it down, so I tried it....booted up in Safe Mode, then shut it back down. When I re-started it normally, it took even longer to re-boot (multiple times now) and my desktop background picture turned back to that starry galaxy. Is it still booting up in safe mode until I change something, or do I just need to re-set things? Its my first mac, so I would appreciate any help. Thanks:)

Meg
01/01/2012 at 01:56 PM