Apple Releases macOS High Sierra Golden Master Candidate to Developers and Public Beta Testers

Apple today seeded a golden master (GM) candidate of macOS High Sierra to developers and public beta testers after nine rounds of betas. The golden master represents the final version of macOS High Sierra that will be released to the public on Monday, September 25, should no additional bugs be found.

The macOS High Sierra golden master can be downloaded from the Apple Developer Center or over-the-air using the Software Update mechanism in the Mac App Store.

macOS High Sierra is designed to build on features first introduced in the macOS Sierra update in 2016, focusing primarily on new storage, video, and graphics technology. The update brings a new Apple File System (APFS), High Efficiency Video Codec (HEVC), new HEIF image encoding, and an updated version of Metal with support for VR and external GPUs.


Multiple apps have been updated with new capabilities in macOS High Sierra. Photos features a new sidebar to make it easier to access editing tools and albums, and there are new filters and editing options like Curves and Selective Color.

Safari is gaining speed enhancements, an option to prevent autoplay videos, and a privacy feature aimed at cutting down on cross-site data tracking. Siri in macOS High Sierra has a new, more natural voice, and Spotlight offers flight status information. iCloud, FaceTime, Notes, and Mail also include useful new features.

Apple plans to release macOS High Sierra to the public on Monday, September 25. macOS High Sierra will run on all machines that are compatible with macOS Sierra.

For a complete overview of changes coming in macOS High Sierra, make sure to check out our macOS High Sierra roundup.

Related Forum: macOS High Sierra

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Top Rated Comments

xmonkey Avatar
100 months ago
Least anticipated Mac OS version ever
You kidding? eGPU support and Apple File System support make this easily one of the better releases in awhile.
Score: 30 Votes (Like | Disagree)
nutmac Avatar
100 months ago
Due to the 32 bit cutoff, I might wait this one out. Don’t feel like upgrading Microsoft office since I don’t use it often; and I have a bunch of old projects in FCP 7 still that I haven’t moved up to 10.
macOS High Sierra runs 32-bit apps just fine (you are probably thinking of iOS 11). Apple has only stated that Mac App Store will stop carrying 32-bit apps early next year.
Score: 8 Votes (Like | Disagree)
Aluminum213 Avatar
100 months ago
Least anticipated Mac OS version ever
Score: 8 Votes (Like | Disagree)
john123 Avatar
100 months ago
Who's quality is worse yours or Apples? "macOS High Sierra that will be released to the public on Monday, September 25 ... Apple plans to release macOS High Sierra to the public on Tuesday, September 19"
You mean "whose"....
Score: 7 Votes (Like | Disagree)
MikhailT Avatar
100 months ago
Build number of the GM build is 17A362a.
Score: 6 Votes (Like | Disagree)
noraa Avatar
100 months ago
Been using High Sierra since the first DP beta, and it's been pretty good so far. The early builds were definitely rough around the edges (to be expected), but the past few builds have been relatively stable. I've noticed a few issues, mainly with iTunes and Photos. When I have iTunes open the computer can slow to a crawl - but not always. I haven't tested it since the 12.7 release of iTunes, so that might help. Photos is just buggy as hell. I have a relatively large photos library (167.7 GB, 18000+ photos and videos, mostly photos), but had few issues under Sierra. There were periods when it would slow down some, but usually when I was importing a bunch of photos while editing existing photos and what not. In High Sierra it can run really slow all the time, in full screen mode I get weird screen artifacts (like a white bar on top, where the toolbar should be - until I mouse over it and the toolbar appears), can crash a lot - typically I get the spinning beach ball of death and have to force quit. I've reported the various issues to Apple, and while Photos has definitely become more stable since DP1, it's still buggy. I'm actually really excited about some of the additional editing features in Photos - will require less use of 3rd party extensions - but at the moment it is rather annoying to use. Hopefully, though, these issues can get ironed out before public release (haven't had a chance to install this GM candidate to test it out).

My biggest cause for concern, however, is APFS. I'm currently running APFS on both my MacBook Pro with dedicated flash storage, and my iMac with a fusion drive. High Sierra automatically updated my MBP to APFS, but did not updated the fusion drive. In fact, I could even manually convert the fusion drive to APFS - I actually wiped my machine completely, recreated the fusion drive and formatted it as APFS (so obviously APFS works with a fusion drive). So far it seems to be running just fine - and there are some obvious benefits to it already. I had a major issue in a recent build that prevented my iMac from booting, I figured I'd have to just restore from a Time Machine backup. Fortunately, because of APFS, Time Machine creates local snapshots on the internal hard drive, and I was able to restore to one of those snapshots prior to the issue I had. It was easy, fast, and actually worked (unlike a similar feature in Windows allowing you to restore the system to a previous point if you're having issues, which rarely works to resolve the issue). With that being said, and speaking of Time Machine backups, external Time Machine backups still need to be formatted as HFS+. It thus appears that at the moment, external Time Machine backups gain no benefit from the new features in APFS (specifically the aforementioned snapshots). I'm sure this will change at some point down the road...but who knows when. Which brings me to my biggest concern about APFS, there's just not a lot out there about it. Apple has published a number of different documents delving into some of the features and specifications about APFS, but there are still a lot of unknowns. The fact that there is no mention of external Time Machine backups in the documents (only local backups are mentioned) and that a lot of API's haven't been published (snapshots, clones, etc) just has me leery, it feels like APFS is still in beta stages. This wouldn't necessarily be an issue, but any machine running just flash (no fusion drive) will be automatically upgraded to APFS, with no option to NOT be upgraded. Hopefully when the final release is available Apple will publish more info on APFS.
Score: 6 Votes (Like | Disagree)