Today, Apple kicked off WWDC 2017; during the keynote, the company announced the next version of macOS, version 10.13 High Sierra. It will bring a number of new features, and will be supported by all Macs that support the existing OS, 10.12 Sierra.
Following the event, the company released a Developer Beta of the OS, promising a Public Beta later on this month. If you're not into taking risks, you should probably wait for that, but if you really need to test out all of the new stuff, read on.
Installing macOS betas are pretty straightforward.
- Go to Apple Developer, and go to Develop -> Downloads.
- The second item on the list will be macOS 10.13; click the download link.
- Open the file that downloads, and follow the onscreen instructions to install it.
- Once that's done, you should land on the page in the Mac App Store for High Sierra. Click the link to obtain it (after you do this, you will find it under the Purchased tab).
- After it downloads, follow the onscreen instructions to install it. You'll be asked if you want to convert your Mac to the Apple File System, unless you have a mid-2012 Mac Pro or iMac with a 3TB Fusion drive and BootCamp, where APFS isn't supported yet.
After your Mac updates, you'll get the usual prompts when setting up a new version of macOS, such as entering your iCloud password and setting up Keychain. Once you're done with that, you're good to go with High Sierra, and updates will come through the App Store.