How to Reset PRAM on a Mac

Nov 15, 2010 - 51 Comments

How to Reset PRAM on Every Mac

Resetting your PRAM (or NVRAM) 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 / NVRAM on Mac

You reset the PRAM / NVRAM by doing the following:

  • Reboot a Mac and then immediately hold down the Command+Option+P+R keys

You will then hear the Mac reboot sound again, signifying that the Macs PRAM or NVRAM 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 and NVRAM on every Mac hardware.

How do you know the PRAM / NVRAM 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 / NVRAM 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.

Apple Silicon Macs are an exception, however, as they apparently do not have NVRAM.

What is PRAM? What is NVRAM?

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

NVRAM stands for Non Volatile Random Access Memory, and it serves the same purpose as PRAM in that it stores information on a memory chip pertaining to various features.

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

  • 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 / NVRAM 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.

NVRAM and PRAM are basically the same thing and serve the same purpose, many users continue to refer to NVRAM as PRAM and vice versa, since their function is the same and resetting the memory is the same, it doesn’t really matter much.

When do you want to reset PRAM / NVRAM?

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 / NVRAM is different than resetting SMC, but both can be effective tools when troubleshooting a Mac to resolve a variety of potential issues.


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


» Comments RSS Feed

  1. GDM Sydney says:

    I have twin screens and one died. Rebooting the PRAM worked a treat. My thanks

  2. Nick says:

    MacBook 4.1 white unibody 2007. Intermittent black screen.
    I removed both of the RAM cards and replugged them in. Then performed the SMC reset twice, that didn’t work for me, but the PRAM did after the second attempt.
    Great fix. Thank you.
    Waiting for new RAM upgrade to 4GB 2x2GB and new 850 EVO SSD 120GB all in the post.
    I was afraid my 10 year old MacBook was dead beyond economical repair. Looking forward to the upgrade on my know functioning laptop. You saved my bacon. Cheers.

  3. Vladimir Rott says:

    iMac with a USB keyboard keeps on searching for a Bluetooth one
    (error of previous post corrected to: Mac OS 10.13.5 + some minor edits done)

    A while ago, after one of the last Mac OS updates, I had to add an extension cable to my USB keyboard. So my iMac can find it, and stops searching for a, non-existent, Bluetooth keyboard instead. A solution (“solution”:) I’ve found back then on the web:
    USB keyboard—USB extension—iMac.

    Today, after updating to Mac OS 10.13.5 (Hi- Sierra), the same problem came up again. Searched the web again, and came to the site and the pages “Mac USB Ports Stopped Working? It’s Likely Easy to Fix” (1), “When and How to Reset Mac SMC (System Management Controller)” (2) and “How to Reset PRAM on a Mac” (3)

    (3) and

    Sounds good:-) Tried (2) and (3) several times.. yet my iMac still says: “keyboard not found”, while keeping on searching for a, non-existent, Bluetooth one.

    What to do? A crazy idea came out of sudden.. I’ve added yet another USB extension.. and voilà, USB keyboard found! So the “solution” is:
    USB keyboard—USB extension #1—USB extension #2—iMac.

    Sounds crazy, but works.. at least for the time being.. just wonder, when my iMac will need a USB extension #3..

    Is there a solution to get back to “USB keyboard—iMac”?

  4. greg says:

    Thanks , i had issues with my partners older style MBPro , it wouldn’t get past the grey screen with timer wheel on boot , one PRAM reset didn’t do it but i held the buttons down for 5 resets and its came back to life , but there is no radar now for turning wifi on and off.

  5. Dallas says:

    Thanks for suggesting that ,you may need to retry the PRAM boot a couple of times,apparently I got it right on the third try ,on my imac.Your advice is much appreciated.

  6. Amanda says:

    Btw it’s a 2008 macbook

  7. Amanda says:

    I’ve tried everything for years to fix my black screen. My apple doesn’t light up but when I shine a light through I can see to type in my password. Still no light after. Can anyone help?

  8. Saakshi says:

    My MacBook Air is not starting. Please help!!!

  9. JuanCa says:

    Great solution!
    Inside DVD unit in my iMac (mid 2011) wasn’t working at all and this fix solve it. It saved me from buying an external unit. Thanks a lot!

  10. Mark Pessoni says:

    I reset myPRAM earlier, although I am hoping this will do the trick.

  11. None of the 3 options worked for me. After trying them multiple times, I had the idea to type in my password, to a completely dark screen, then hit enter. Voila! My computer is back!

  12. Robert B says:

    I have an Imac which was working fine, but appeared as though the WiFi was not working even though the icon showed connection.

    After several attempts to get the WiFi working again, I restarted the machine. The result was a white (grey) screen with a folder ? flashing.

    I attempted to restart again to no avail. I have followed all of the different suggestions to reset both PRAM, NVRAM and SMC all to no avail. I’ve tried the reset up to 15 times in a row and nothing. Any suggestions short of a new hard disk?

    Thanks very much

  13. Pat K. says:

    PRAM works for me after lress and hold couple of times. Worth all tries. Thank you thank you my life saver :)

  14. Worked perfectly, thank you

  15. Jason G says:


  16. Jason G says:


    Reset PRAM: shut down, Command+Option+P+R keys, power on and hold Command+Option+P+R keys until chime rings again, then release

    Reset SMC: unplug, shut down, plug in, hold SHIFT + OPTION + COMMAND + POWER then quickly release

    I also did the renaming tips from you on the Airport

  17. DCita says:

    PRAM resetting worked fast, after no effect with the first two metods! Thanks a lot :)
    MacBook Pro 3.1

  18. feng says:

    My Macbook air had a black screen and it seemed none of the tricks worked until I tried PRAM by pressing the power button + command+option+P+R keys THE SAME TIME. Now my computer is back to normal! Thank you!

  19. Cauli says:

    Thank. You

  20. adam says:

    how to fix USB port problem if its the hardware?

  21. Hi all says:

    I have issue with my MacBook Pro 2011 (el capitan 10.11.3), It is shutting down after put my password. He is start to load but alomust on half of loading proces is shuting down. I don’t know what to do. Please help.

    All the best,

  22. Chris says:

    So I’m having an issue, everything was fine until wireless router went bad last night. I tried restarting and locked up on grey screen, progress bar goes to about 2/3’s and just locks up. First I tried resetting PRAM, no change. Then tried resetting smc, the only change is that when I power off and back on the screen background changes from gray to tan and back and the progress bar briefly flashes a larger white empty box, then the bar reappears but stops at the same point every time. Any ideas would be greatly appreciated.

  23. DAPG says:

    The third option, PRAM reset, worked on our Macbook Pro. Your tips saved us a trip to the Apple Store. Thanks

  24. Dev says:

    Yes, the third option of resetting PRAM worked on my McBook Pro retina. Thank you. Wonder what causes this black screen problem.

  25. mo says:

    Third option pram reset worked for me as well …Thanks !

  26. Tyler says:

    The PRAM reset worked for my macbook pro 2011. I thought it was toast but once I performed the reset, it had me sign into my wifi .. then I went up to the apple icon in the top left and selected “start up disk” and found my HD and selected, restarted and boom, it’s up and working again. I have no idea what caused this, but I’m glad its working now. Thanks guys.

  27. nouhayach says:

    i have already trying the nvram but not working ?
    how resolve it please
    i don’t have sound in my macbook air

  28. Don says:

    Thanks a lot.

  29. Laishram Robin says:

    Can anyone tell me ..what must have been the reason that makes PRAM resetting solved…will it be needed over n over again.. frequently or ance for all ..

  30. Laishram Robin says:

    Thanks… it solved battery misreading… as of now…. and hope it last….

  31. Htet lynn says:

    Thanks !! PRAM reset works!! I can be back on my air again!!

  32. JJ mc says:

    Thanks that’s absolutely brilliant it worked! Thank you so much

  33. Kirsty says:

    Hi i have tried pram reset and smc but still have black screen. Managed get the chime with the pram reset but still gone back. To black. Help much appreciated as travelling. Kirsty
    The only light i have on the machine are the small power lights on the left side. Other than that it is dead for no reason as i shut down as normal.

  34. Scott says:

    Yay! The last fix (PRAM reset) worked.

  35. Shawn says:

    Resetting the PRAM solved my black screen issue

  36. Senthil Kumar CT says:

    Guys I never reply to any help sites but this one here up is a bummer !! Saved my new mac which I thought damaged ! Thanks a lot guys. Saved my day.

  37. 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

  38. 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.

  39. Itay says:

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

  40. 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.

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

  42. 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!

  43. Jeff says:

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

  44. 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.

  45. 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.

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

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