Apple has made OS X Yosemite available to download on your Mac. Here's how you can get your Mac ready for OS X Yosemite, and how you can download OS X Yosemite onto your Mac.
Read our Yosemite pros and cons
How to download & install OS X Yosemite on your Mac
Apple has finally released OS X Yosemite. You'll now find it on the Mac App Store. In order to download and install the new operating system, simply open the Mac App Store on your Mac, or click here and follow the on-screen instructions. Before you do, though, you should prepare your Mac for the update by following the steps listed here.
Also, it's worth noting that it could take several hours to download and install Yosemite.
In the meantime, read our ultimate Yosemite tips
How to prepare your Mac for OS X Yosemite
Just as with Mavericks (OS X 10.9), Yosemite is free and is pretty easy to install. However, before you perform any big update to OS X, you should complete a few tasks to ensure that your Mac is ready to go. Read next: OS X Mavericks vs OS X Yosemite.
Before installing a new operating system it's worth doing a bit of housework. Here are ten things you really ought to do before OS X 10.10 launches (and you'd better hurry because that could be today!)
See also: Explore Yosemite's iTunes 12
1. Find out if your Mac will be able to run OS X 10.10 Yosemite
This one is a biggy. If your Mac can't run OS X 10.10 Yosemite then I'm afraid there's no new software update for you. Don't panic, though, Apple has kept the list of supported Macs the same as the supported Macs for OS X Mavericks, so if you're already running Mavericks you'll be able to get Yosemite.
You'll find a full list of the supported Macs in our Will your Mac run OS X 10.10 Yosemite article.
Check the specs of your system by clicking on the Apple logo on the top left of your screen and selecting About This Mac.
2. Make sure you have sufficient RAM to run OS X 10.10
If your Mac is on the list of supported machines, it's likely you won't run into any problems, but it's worth checking that you also have enough RAM to run OS X Yosemite. Apple says you'll need at least 2GB RAM, although 4GB is advisable. If you have less than 4GB RAM it might be time to consider upgrading to a new Mac, or installing more RAM – if you decide to do that, make sure that the RAM you choose is compatible.
Read about how to update the RAM in your Mac here.
3. Make sure you have enough space for OS X 10.10 Yosemite
Apple suggests that you should have 8GB of free space on your Mac's drive before you install a major OS X update, but we recommend aiming for 15GB to 20GB. The Yosemite installer is 5.16GB, and you'll need to allow some room for temporary files.
Here's an article about freeing up space on your Mac.
4. Get access to the Mac App Store
If you are still running Leopard and don't have access to the Mac App Store you really really really need to upgrade! The next version of OS X will be available only via the Mac App Store and the Mac App Store arrived in Mac OS X 10.6 Snow Leopard. Luckily you can still get hold of a copy of Snow Leopard from Apple. It costs £14.
Read our article that explains how to get a copy of Snow Leopard.
5. Update your software for OS X 10.10 Yosemite
Make sure you install the latest updates to Snow Leopard, Lion, Mountain Lion or Mavericks (whichever you're currently running) before upgrading to OS X 10.10 Yosemite.
To make sure you are up to date, click on the App Store icon in the Dock and select Updates. You can also click on the Apple logo at the top left of your screen and select Software Update from there.
6. Update your third party apps
Make sure you have updated any third party apps too. Those updates may include changes that are required for upgrading to Yosemite and if you don't run the updates they may not work properly once you have updated.
To update apps you've bought from the Mac App Store, launch the App Store app and click the Updates button in the toolbar. Then click Update All, simply providing your Apple ID and password when prompted.
For apps that you purchased elsewhere you'll need to manually install updates. You can check if there are updates available from the application's menu, in Microsoft Word, for example, it's a case of clicking on Help > Check for Updates.
Check compatibility with your third party apps before installing OS X 10.10. That way you will be up and running immediately, rather than being frustrated by your favorite apps and add-ons not working.
We will feature a list of apps that don't work with Yosemite as soon as we know of any issues.
7. Ditch really old software
If you're still running Snow Leopard (OS X 10.6), you may still be using a few PowerPC programs - software that was never updated to run natively on Macs with Intel processors. Apple used to provided software called Rosetta that translated PowerPC code so it could run on Intel Macs. When Snow Leopard (OS X 10.6) launched Rosetta was no longer installed by default, but it was possible to download and install Rosetta if you wanted to run a PowerPC program. However, Apple killed Rosetta completely when Lion (10.7) was released, and it remains unavailable to this day.
Any PowerPC apps you have won't work when you update your system, so you'll either need to ditch them and find alternatives, or stay in the dark ages and run very old software.
To find out if any of your applications are PowerPC programs, launch Snow Leopard's System Profiler utility (in /Applications/Utilities), select Applications (under Software in the sidebar), and then click the Kind column header, which sorts the list of applications by processor type. Any programs listed as PowerPC will not work under Yosemite, they won't even work in Mavericks, Mountain Lion, or Lion.
8. Make sure your Mac is healthy
You should make sure that your Mac is completely healthy before installing a big update to the system.
Open Disk Utility (in /Applications/Utilities), select your startup drive from the list on the left, click the First Aid tab to the right, and then click Verify. If Disk Utility finds problems, you'll need to boot from a different volume to perform the actual repairs using the Repair Disk button.
Boot into recovery mode (by holding down Command+R at startup) and use Disk Utility from there to perform the recommended repairs.
Read more about using Disk Repair to fix a Mac here.
9. Back up your Mac
Before updating to OS X 10.10 we recommend that you back up your Mac, and test that the back up worked before you do anything else. You can use Apple's Time Machine to create a back up that will recover your Mac exactly the way you left it prior to the install, but alternatives include SuperDuper or Carbon Copy Cloner both of which will create a bootable clone backup of your Mac.
Read more about backing up your Mac using Time Machine here.
10. Set up iCloud
When you install OS X 10.10 you are likely to be pestered for your iCloud details because these days iCloud is heavily integrated into many apps and system services. Make sure you are logged into iCloud and enable syncing before you start updating and things should go smoothly.