How to Reset PRAM on a Mac

Nov 15, 2010 - 12 Comments

How to Reset PRAM on Every Mac

Resetting your PRAM is a common troubleshooting technique when a Mac is misbehaving. We’ll cover how to reset PRAM on any Mac, as well as providing some additional information about PRAM and what it is to better help you understand when and why you’d want to reset it.

Resetting the PRAM

You reset the PRAM by rebooting a Mac and then immediately holding down the Command+Option+P+R keys, you will then hear the Mac reboot sound again, signifying that the Macs PRAM has been reset successfully.

You must hit the key combination before the grey screen appears otherwise it won’t work, you may need to try it once or twice until you get the timing right during restart, but once it works you can let the Mac system start as usual.

How to Reset PRAM on All Macs

This works to reset the PRAM on every Mac hardware.

How do you know the PRAM is reset?

The PRAM has been reset only if you hear the Mac reboot sound a total of two times – once for the initial reboot and again when the PRAM has been reset (technically you can keep holding down the key combo and reboot the Mac over and over, but there is no practical reason to do so). You can then let your Mac boot up as usual.

Does resetting PRAM work on all Macs?

Yes, the command combination to rest PRAM has been the same for ages, and it works on all Macs, whether they are brand new MacBook Pro, Retina iMac, MacBook Air, Intel or PPC architecture, a MacBook, iMac, or a Mac Mini, or virtually any other Mac that has been made, the key command is the same and the effect is the same. The key sequence is the same, as is the process of pressing the sequence immediately on boot.

What is PRAM?

PRAM stands for Parameter RAM, and it holds assorted information about your Mac so that it functions to your specifications.

In no particular order, here are some things stored in PRAM:

  • Startup disk
  • Disk caches
  • RAM disks
  • Virtual Memory (commonly called swap)
  • 32-bit addressing
  • Video and display information including monitor depth, refresh rate, screen resolution, and number of colors
  • Volume for both system startup and speaker
  • Time zone information
  • Mouse and trackpad scaling and speed information (commonly called mouse acceleration)
  • Keyboard repeat rate
  • Kernel Panic information
  • DVD region settings
  • Default system fonts

When you reset the PRAM this information gets cleared out of the Mac. Because of the information stored in PRAM, if you reset the PRAM you’ll often have to readjust things like your mouse tracking speed, time zone (if it’s not set to an online server), and any non-native resolution that any attached display is running.

When do you want to reset PRAM?

reset pram You generally only reset PRAM when troubleshooting something that is directly related to the above listed contents of the parameter RAM, outside of resolving problems or adjusting hardware changes there isn’t much other use for doing so. This can include troubleshooting everything from unusual issues encountered on system boot, to peculiar behavior and performance, to improper screen resolutions, amongst other things.

Do note that resetting PRAM is different than resetting SMC, but both can be effective tools when troubleshooting a Mac to resolve a variety of potential issues.

Enjoy this tip? Subscribe to the OSXDaily newsletter to get more of our great Apple tips, tricks, and important news delivered to your inbox! Enter your email address below:

Related articles:

Posted by: Paul Horowitz in Mac, Tips & Tricks, Troubleshooting


» Comments RSS Feed

  1. […] tried rebooting, you’ve reset the PRAM, you’ve done it all, but your Mac is still behaving strangely. What next? In certain […]

  2. Desmond says:

    Seems like an odd collection of data that is stored within this PRAM, but good to know if things go a bit haywire.

  3. Louis says:

    Actually – if you continue to hold down the key combo and let the mac continue to reboot – it will reset other parts of the mac. I don’t know exactly which ones are which but i know that five restarts will reset the network hardware. At least, that is how it used to be.

  4. Jeff says:

    Have to say removing the memory and doing pram reset was freaking genius!! THANKS SO MUCH!

  5. patricia says:

    I just upgraded my memory from 4 GB to 8 GB on my macbook pro. Do I need to reset the PRAM? Someone had suggested this though before I do it want to make sure. Thanks!

  6. Thank you! My mac was dropping the internet connection every few minutes, and this fixed it :)

  7. Bie says:

    Yes, finally something that worked! Thank you!!! Been having trouble with wifi-connection on my MBP after installing to Maverick (kept falling out). Been trying a lot of things, but this was the only thing working for me. So happy now.

  8. Itay says:

    I have a Bluetooth keyboard which lags on the reboot. Is there any other way to reset the PRAM?

  9. Mahdi says:

    My mac don’t work good the trak pad is not controlable sometimes .i reset msc but also don’t work.if i reset pram is work good?

    • who knows says:

      Why don’t you try resetting the PRAM and SMC and letting us know if that works to resolve whatever you are experiencing on your Mac.

    • Line says:

      it could be your battery the issue, i had that problem and didnt know but the battery underneath it was getting a bit swollen. no visible mind you. i bought a no name battery online for 50$ same battery, same serial number on it, it just dont have the apple logo. it fixed the track pad issue immediately.

      use your laptop plugged in and with no battery, see if your track pad works better. if so, then you found the problem.

  10. Mahdi says:

    I reseted PRAM & SMC but also don’t work worked good i charged my mobile to it after three or four times this problem found.
    Is it possible its battery had problem?
    Because its work about 3-4hours. before charging it worked about 5-6hours

Leave a Reply


Shop for Apple & Mac Deals on

Subscribe to OSXDaily

Subscribe to RSS Subscribe to Twitter Feed Follow on Facebook Subscribe to eMail Updates