How to install Yosemite right now without ruining your Mac



OS X 10.10 Yosemite is gorgeous. It’s the biggest visual overhaul to come to OS X since Aqua, which has caused a rush of Apple fanboys – including our own Leander Kahney –  to jump the gun and install the buttery smooth interface on every Mac in sight.

Playing around with Apple’s newest software is a true tech delight, but it can also come with some horrific consequences if you install it as your main OS, as most apps still aren’t optimized for the update. However, unlike iOS 8 there’s a safe way to install it without ruining your Mac until the final version is ready.

Here’s how to install the Yosemite beta in the most responsible way possible:

What you’ll need…


OS X 10.10 Developer Preview – Developers can grab the preview through the Dev Center. Not a dev? You could sign up for the new OS X Beta Program and wait for Apple to finally send out invites, or you can download it right here.

Storage Space – If you’re tight on hard drive space you’ll need to free up at least 20GB or more before beginning the partitioning and installation process.


 Creating a safe place…


Rather than slapping OS X Yosemite right over your current version of Mavericks, you can make the testing process much less painful by creating a separate partition to keep the bugs from affecting your finely tuned workflow on Mavericks.

  1. Open Disk Utility by going to Applications >> Utilities >> Disk Utility
  2. Select your Mac’s main hard drive (the top one above Macintosh HD)
  3. Click the Partition tab
  4. Click the + underneath the Partition Layout section
  5. Name the partition and set the amount of GB you want to allocate to it
  6. Click “Apply”

After a few seconds of churning you will now have a second partition on your Mac. Now just load up your OS X 10.10 installer and after a few screens you’ll  see the option to select which disk to put Yosemite on.


Switching back to Mavericks..



At some point you’ll undoubtedly get tired of the bugs and broken features in the Yosemite beta, but if you created a partition you can slip back into the sweet delights of OS X Mavericks by changing your Startup Disk.

  1. Open System Preferences
  2. Click “Startup Disk”
  3. Select your original OS X 10.9 partition
  4. Click Restart and BOOM, you’re back enjoying the cleaner shores of Mavericks
  • Michael Hoffman

    wouldn’t it just be easier to install mavericks in a VM using vmware, virtual box or parallels?

    • whodakat

      The new betas almost always break virtualization software. I can’t speak for vmware or vb, but parallels does not work. This partition idea is a great way to go, if you want to check 10.10 out now.

      • Asteng88

        Parallels doesn’t even work on a clean install of mavericks. Once you install parallel tools it all stops working.
        VMWare Fusion is the way to go.

  • Wayne Morse

    This may be a dumb question, but is it advisable to sign in with your apple id on this release?

    • Eric

      Yes, it need to sign in. Because, this is a beta test for “developers” only (the makers of apps).If you are an Apple developer and registered to Apple Developer, you’ll have to sign with your apple id.

      • Wayne Morse

        Ok, I’m not a Dev…I have my apple id registered but I have not paid the $99 so I only have access to current OS tools. I’m not sure if I should sign in with mine or not.

      • Martin Adams

        Sign in.. Its fine really.

      • Jakub Jenigar

        Are u sure?

      • Asteng88


    • dpacemaker

      You can also sign up for the public beta. If there are slots still available, then you don’t need to pay the 99$ fee.

      • Mark Benjamin David

        also, you can sign-in w/apple id, but skip using iCloud Drive, I skipped iCloud Drive and the beta seems to be working fine with regular iCloud stuff. (I don’t use iCloud for photo-streams, but most other things.)

  • Pompo

    there are three files there from your link you posted under ” download it right here.” . Which on should I download? The middle one only?

    • BusterH

      you can use the torrent file, or try the direct download link

    • Martin Adams

      You want OS X Yosemite DP1 (Fixed), and direct download through Chrome..

    • montana winter

      None of them. The link is BS and a waste of time. You get 2 choices on each of them, direct or torrent. The direct download is just a link to a scam page to get you to buy stuff and the bit torrent download image does not work. I guess we need to wait to be invited.

      Most of the time, it just hangs on beginning loading and nothing ever happens. When it does, the page attached below is what you finally get to for the direct download. Clicking on download either gets you an error (never starts downloading) or a spam page to download MacKeeper or other aps.

  • Cody Throndson

    So will this work if you are not a dev? Because from what i”m hearing is that you must sign in with your apple ID and be verified to run the software.

    • Martin Adams

      If you cannot login, try signing up to this: but don’t pay.

      My Apple ID is registered to that, but I am not paying… and I signed in and running fine (as primary OS.. apart from VMWare & Private IMAP mail, all works reasonably stable.)

  • wersplat

    don’t use trim support if using third party SSDs, will cause a hang on startup…only way to fix is to reinstall

  • So many of the cool new features aren’t even in the DP1 version yet that it’s not worth installing for the average (impatient) person. “Dark Mode” comes to mind.

  • Rodolfo Santos

    Anyone know how I can uninstall Yosemite? Apparently the installation of Yosemite created a Logical Volume Group with two logical partitions and I don’t know how to get back to the original configuration with only one partition with Mavericks…


    • Mitch Sebastion Koshney Peters

      The same way you created a partition, instead of the + button there is the – button.

    • Kevin M

      I’m having the same problem. I’m assuming you “-” is greyed out so you can’t delete the partition. That’s what I’ve got going on.

      • I wonder if you can only remove a partition by erasing the whole drive?
        If that is so and you don’t want to erase, can you reduce the size of the partition to really small?

        PS do backups still work in your main partition?

      • Kevin M

        Everything works fine. I was actually going to increase the size of the Yosemite partition and that’s when I ran into this. I made a clone of the startup/main drive and that is ok.

        Every option is greyed out in relation to partitioning or reformatting. I can erase the two different partitions but that doesn’t really solve anything. I’ll need to figure out a way to completely reformat the drive back to a Guid Partition Table.

      • Raj

        Erase the contents in “Yosemite Tester” using Disk Utility. As soon as its erased, the “-” will become functional. Remove it using “-“, then pull down the main partition

  • craig allen

    Anyone know if it’s possible to run 10.10 from an external hard drive?

    • Ali Yenigün

      It is not possible to run OS X on an external hard drive. This also counts for Windows

      • Lionello

        Windows not, osx yes.

      • Eitot

        It’s possible to run OS X on external storage. You only need a Mac to boot it.

      • BMWTwisty

        I have Yosemite installed on a 64GB Sandisk Extreme Micro SDXC card installed in a Nifty Drive adaptor on my 13″ MBP. It works just fine.

      • As has been said, it is possible to install OSX on ext. HD – see

    • Lionello

      It’s possible. I did it this morning with 10.10.

      • craig allen

        Excellent! Same process as above? Except for partition the hard drive I assume… You didnt have to wipe the drive first did you? Thanks!

      • Lionello

        I had a spare external USB disk and I had to wipe the disk. As tara as I know, if you repartition the drive, you have to format the drive. I don’t know if there is a secure method (except for Bootcamp / windows install) to resize a partition to make room for another OS X installation.

  • Michael S

    Does this work with the free beta software? When I go to install it, it says “Beta Access Utility can’t be installed on this disk. You can only install this software on the disk that is running OS X.” The format under the “Partition” tab is Mac OS extended. Am I just doing something wrong?

    • ndust

      make sure when you partition it it says it guid format for os x system

  • Jon

    But if you have bootcamp installed, how do you create extra partition after that?

    • I have the same problem. Cannot re partition it at all!

  • Erik Moust

    I get the following message:

    The Install OS X 10.10 Developer Preview application can’t be used from this disk.

    Copy this application to a writable Mac OS Extended formatted disk and reopen it to continue installation.

  • Lasse Fernov Sørensen

    Ok so i’ve installed the thing now and restarted, but it wont accept my password at the login screen. It shows my usual password hint – but password wont work. Help??

  • Guest

    Ive installed on a new partition and restarted – but at the login screen it wont accept my password? It even shows my usual password hint. Help??

  • Leovinius

    I love this on my Mac, messing with an active partition on the fly and the damned thing still starts. Do that on a Windows machine and you’re looking at 4 hours of fixing boot.ini or restoring a disk image.

    Windows fans, feel free to downvote me for having a computer I like. Losing imaginary internet points really upsets me.

    • altechi

      Disquis doesn’t allow down voting anymore

  • Guest

    i just cant make partition it keeps giving me this error

  • Technocrz!

    im having making partition issue below is the screen shot of error:

    Partition failed with error:
    couldn’t modify partition map because file system verification failed.

    • Dhenny Ananda

      I have same problem like this, does anyone know how to fixed it?

      • ew29fan

        I had the same problem, but I rebooted on the Recovery disk and ran disk repair. Once that was done, it worked. I noticed that you are only creating 20GB, and I would recommend more. The installed OS is nearly 20GB and you won’t have space to install updates. I would do at least 40GB if you can spare the space.

  • logan Carvalho

    When you said: Without ruining your mac, I think it would be true. I partitioned my Mac’s main hard drive in order to install the beta version, but no one told me it would ruin my other partition known as Bootcamp. It simply disappeared. I can’t find as a start up option, haven’t you tried it? you guys make me not believe in what you say…

    • xared

      Yup got the same here. If Bootcamp’s there, this method makes it impossible to startup in Windows. Better backup what you can from that partition.

      I ended up deleting the Bootcamp and then trying to increase the OS X partition to full size. What I didnt realise is that the recovery partition got messed up too coz of that: it is 650 MB and is kept right after the main partition.

      So finally unhided all partitions, deleted recovery, recreated it again (using a tutorial I am linking below).

      A little usage help (keep the Mavericks installer .app ready)

      Download ‘Recovery partition Creator’ here:

      Heck, it was a lot of time spent on finding all this. Hope it helps someone.

      • logan Carvalho

        Thank you for sharing your solution. I didn’t know what I had in mind to try it. After searching a lot I found a solution that worked without the need to erase the partition. I used, Refit software and after some restarting, it worked perfectly.

    • shivam89

      Still have it over here, but I upgraded mavericks to Yosemite, have no probs to use a daily driver. Can still boot in Windows and access bootcamp (Macbook Air 2014/mid-2013)

  • Gerald Santos

    If I delete the “Yosemite Tesster” partition will the OS X Yosemite get deleted, too?

  • José Miguel Beltré Paulino

    Don’t works the integration with Wikipedia, Maps, Movie in Spotlight…

  • Martin

    How can I delete the Yosemite partition?

  • I thought that it was not possible to partition a drive without first erasing it? Looks like as long as you have enough space you can do it?

    A lot of people have commented how they cannot delete the partition though. So do you need to erase a disk in order to remove a partition?

  • Atmospheric Music

    I have two Mac’s. One iMac (Mid 2012) and one Macbook Air (Late 2013).

    So I had a hard time deciding where to install the developer preview but it came down to my iMac. So the first time I installed it, I messed up because I installed it over a fully loaded Mavericks which made it lag, so I had to re-install Mavericks, then re-install the developer preview on a clean version of Mavericks and this time it worked perfect.

    I’ve used my iMac everyday since 2nd of June with only Yosemite installed and I have no issues with it what so ever. Sure there are bugs and coding errors but nothing that breaks the OS. It works smooth, Safari has not had any bugs or anything.

    The only thing that annoys me would be that the whole OS slows down when you leave it on sleeping mode and turn it back on after some hours and then you have to restart.

  • Sharel Hun

    i have registered to the beta tester and downloaded Mavericks Beta AccessUtility app.backed up my mavericks and installed the utility app,it finishes the install and opened the mac App Store at the update tab but won’t give me the Yosemite download says i don’t have any update. can u help me?

  • Sharel Hun

    i have registered to the beta tester and downloaded Mavericks Beta AccessUtility app.backed up my mavericks and installed the utility app,it finishes the install and opened the mac App Store at the update tab but won’t give me the Yosemite download link. it says i don’t have any update. can u help me?

  • xared

    A word of caution: dont try this if you have Bootcamp. My Bootcamp & Recovery partitions were screwed.

  • Daniel Hampton

    I have made a video showing how to get and install it for free withought a developer account. I also provide my OWN LINKS for download! Check it out for me?

  • adam

    mine gives me this error when I try to install it to the partition

    • Revolverkiller

      yeah me too, got it from the mega link

  • Baseballguy2001

    Anyone try on an external drive?

    • I asked a guy at the Apple Store about partitioning a drive. He said it isn’t possible to partition a Mac HD for two versions of OSX. Don’t know if I believe that but he did say to use an external hard drive. I am going to use that method as it will make my life easier not having to partition my HD.

      • Baseballguy2001

        That sounds like the safe play Dan. I have a couple of spare drives lying around, if I try I’ll let you know.

      • I’ve now installed Yosemite on an external hard drive. Straightforward installation and working well.

      • Baseballguy2001

        I installed it yesterday morning without a hitch on a drive in sled 2 of my 2008 Mac Pro. It runs just fine. It’s different, but everything so far appears to work. No crashes, no freeze ups.

  • Cristian Nicula

    Can I use my files under both Mavericks and Yosemite?

  • prik67

    this is what shows up even after I choose the correct partition on which I intend to install Yosemite ..

  • prik67

    I forgot to upload the screenshot of the error message that pop up while trying to install Yosemite on a different partition.

  • xared

    Hey Buster, please do warn users to not attempt this when they have a Bootcamp partition. Doing so makes the Bootcamp inaccessible, due to changes in the EFI. Will have to then mess around with REFIt.

  • David Thomsson

    If i install it on my MBA and it crashes or something makes it unusable will Apple fix it?

    • Kr00

      Do you understand what the term “Beta” even means? I suggest you find out, then read the disclaimer Apple asks you read when you sign up for the beta program.

    • Kr00

      “Things you should know before installing OS X Yosemite Beta:
      This is beta software that is still in development, which means some applications and services may not work as expected.
      We recommend installing OS X Yosemite Beta on a secondary Mac. For important information about resetting your Mac to OS X Mavericks, click here.
      Important note: Enabling iCloud Drive during setup will disable iCloud Documents and Data for all your existing devices. Learn More”

  • That’s a cheap BMW. If you really worked for Google you might be able to afford a real one. Also I fail to see the benefit of this “offer” if it took you 8 months to afford a cheap fourth hand car?

    Love how you voted up your own spam!!!

  • I installed it on my Newton Messagepad 2100. :)

  • Marcus Winchester

    Just finished installing it on my Retina MacBook Pro, for a beta release, it is incredibly stabile. The major issue plaguing it at the moment seems to be in the battery life department, its on par with the battery life I normally get running Windows 8 under Bootcamp, so roughly 6 hours of battery life, not bad given its early days with the releases. I didn’t like the new Finder icon so i restored the old one but I have one question, WHERE IS THE NEW iTUNES?

  • Marcus Winchester

    Safest way for users with other partitions on their internal drive( e.g Windows or Linux) is to back Mavericks onto an external drive using Time Machine and then replace Mavericks on the internal drive with Yosemite. Very simple process, it was much easier and quicker than it was installing Windows 8 on the Mac under Bootcamp. Ignore the method in this article, pertaining your main drive if you already have partitions for other OS’s is a BIG NO NO. I have tested to make sure my Win 8 partition works and it does

    • Cristian Nicula

      Do you know if I can use my files under both Mavericks and Yosemite?

  • TJ Liwanag

    great. now that i have it, what do i do when i eventually want to remove the partition??

  • TonyC

    Having just received the notice of the general availability of the beta, I’m going to work on that this weekend. My plan is to image my current drive, using SuperDuper!, onto a spare 500gb drive I took out of a defunct macbook (I’ll use a docking station). I’ll the boot onto that and install Yosemite. I feel that will give me the best test of how it will install and look on my system I can do (taking into account the marginal performance of the USB 2 connection). I can shut it off as desired and not use any space on my working drive.

  • I successfully installed Yosemite today on a partition I made out of the free space on my hard drive. Everything went flawlessly.

  • Emir Erdoğdu

    Can I erase the partition after Yosemite fully released and make my disk full like before.

    • Guest

      I was gonna ask the same question.

  • Mrinal

    I am getting this error message.. I created the partition and everything but as soon as i start to install the .pkg file and choose the install location to be the new partition i created i get to this screen

    • Revolverkiller

      I wanna know what this is all about, i got this too when i tried to install on another partition

  • Karl-Emmanuel Barrière

    I just got a little scare this morning: I installed the public beta on a new partition last night and got to play with all the new blur of Yo’ but when I booted up this morning, my Mavericks partition wasn’t recognized on startup (holding Option). The 10.9 recovery wasn’t available either. I had to physically removed my SSD and boot externally via USB to make sure my MBP didn’t go straight for the Yosemite partition, but I could only see the 10.9 Recovery. So I launched it, checked and repaired the disk from Disk utility and voilà! I’m back on Mavericks!

  • Installed Yosemite on my main MacBook Pro yesterday. Everything so far works like a charm incl. Parallels, Chrome Browser, MS Office and of course all Apple apps. Only app that can’t be used is running on Java Runtime and requests an older version of that. Just use it in Windows 7 on the virtual machine without problem.

    The new interface rocks. Like it a lot.

  • Nishad Gurav

    Ive backed up data using Time Machine. So if anything gets screwed, Im safe

  • Robert Trance

    I replaced Mavericks actually with Yosemite PB when came out…and…..hell, pretty good. Took a risk, certainly, but, everything i need daily works! Liking the release so far…Curious if i run against problems and what kind. Of course i have a USB image of Mavericks….

  • Chris

    I cloned my Mavericks partition onto an external hdd then booted into it. Downloaded the PB and attempted to install. Now all it tells me is the download was corrupted and I need to redownload. Tried it one more time with same results. Not sure where to go from here.

  • Mark Benjamin David

    uh, won’t you have to erase your entire drive to create a new partition??

  • Velanche

    Thanks for the directions; works like a charm! Great idea on keeping both OS separate.

  • Yosemite successfully installed on external hard drive. Very straightforward installation and working well. Really liking the new interface. But the best is yet to come with Continuity etc!