Apple Seeds Third Beta of macOS Sierra 10.12.6 to Developers [Update: Public Beta Available]

Apple today seeded the third beta of an upcoming macOS Sierra 10.12.6 update to developers, two weeks after seeding the second 10.12.6 beta and a month after introducing macOS Sierra 10.12.5.

macOS Sierra 10.12.6 can be downloaded through the Apple Developer Center or through the Software Update mechanism in the Mac App Store.

10
No significant features or notable bug fixes were found in the first two macOS Sierra 10.12.6 betas, and because Apple does not provide beta release notes, we may not know what's included in the update until it sees a public release.

macOS Sierra 10.12.6 is likely to be one of the final updates to the Sierra operating system as Apple transitions to macOS High Sierra, which was introduced at the Worldwide Developers Conference in June.

Update: The third beta of macOS Sierra 10.12.6 is also available for public beta testers.

Related Forum: macOS Sierra

Popular Stories

iOS 26 Feature

iOS 26.1 to iOS 26.4 Will Add These New Features to Your iPhone

Saturday October 18, 2025 11:00 am PDT by
iOS 26 was released last month, but the software train never stops, and iOS 26.1 beta testing is already underway. So far, iOS 26.1 makes both Apple Intelligence and Live Translation on compatible AirPods available in additional languages, and it includes some other minor changes across the Apple Music, Calendar, Photos, Clock, and Safari apps. More features and changes will follow in future ...
ios 26 1 liquid glass opaque

iOS 26.1 Beta 4 Lets Users Control Liquid Glass Transparency with New Toggle

Monday October 20, 2025 10:57 am PDT by
With the fourth betas of iOS 26.1, iPadOS 26.1, and macOS 26.1, Apple has introduced a new setting that's designed to allow users to customize the look of Liquid Glass. The toggle lets users select from a clear look for Liquid Glass, or a tinted look. Clear is the current Liquid Glass design, which is more transparent and shows the background underneath buttons, bars, and menus, while tinted ...
iphone air thickness

Apple Said to Cut iPhone Air Production Amid Underwhelming Sales

Friday October 17, 2025 8:29 am PDT by
Apple plans to cut production of the iPhone Air amid underwhelming sales performance, Japan's Mizuho Securities believes (via The Elec). The Japanese investment banking and securities firm claims that the iPhone 17 Pro and iPhone 17 Pro Max are seeing higher sales than their predecessors during the same period last year, while the standard iPhone 17 is a major success, performing...
iOS 26

iOS 26.0.2 Update for iPhones Coming Soon

Friday October 17, 2025 7:35 am PDT by
Apple's software engineers continue to internally test iOS 26.0.2, according to MacRumors logs, which have been a reliable indicator of upcoming iOS versions. iOS 26.0.2 will be a minor update that addresses bugs and/or security vulnerabilities, but we do not know any specific details yet. The update will likely be released by the end of next week. Last month, Apple released iOS 26.0.1,...
Apple iPad Pro hero M5

New iPad Pro Has Six Key Upgrades Beyond M5 Chip

Saturday October 18, 2025 10:57 am PDT by
While the new iPad Pro's headline feature is the M5 chip, the device has some other changes, including N1 and C1X chips, faster storage speeds, and more. With the M5 chip, the new iPad Pro has up to a 20% faster CPU and up to a 40% faster GPU compared to the previous model with the M4 chip, according to Geekbench 6 results. Keep in mind that 256GB and 512GB configurations have a 9-core CPU,...
iPhone Siri Glow

Some Apple Employees Have 'Concerns' About iOS 26.4's Revamped Siri

Sunday October 19, 2025 7:39 am PDT by
iOS 26.4 is expected to introduce a revamped version of Siri powered by Apple Intelligence, but not everyone is satisfied with how well it works. In his Power On newsletter today, Bloomberg's Mark Gurman said some of Apple's software engineers have "concerns" about the overhauled Siri's performance. However, he did not provide any specific details about the shortcomings. iOS 26.4 will...
HomePod mini and Apple TV

Apple's Next Rumored Products: New HomePod Mini, Apple TV, and More

Thursday October 16, 2025 9:13 am PDT by
Apple on Wednesday updated the 14-inch MacBook Pro, iPad Pro, and Vision Pro with its next-generation M5 chip, but previous rumors have indicated that the company still plans to announce at least a few additional products before the end of the year. The following Apple products have at one point been rumored to be updated in 2025, although it is unclear if the timeframe for any of them has...
maxresdefault

Here's How the iOS 26.1 Transparency Toggle Changes Liquid Glass

Monday October 20, 2025 1:55 pm PDT by
With the fourth beta of iOS 26.1, Apple added a toggle that makes Liquid Glass more opaque and reduces transparency. We tested the beta to see where the toggle works and what it looks like. Subscribe to the MacRumors YouTube channel for more videos. If you have the latest iOS 26.1 beta, you can go to Settings > Display and Brightness to get to the new option. Tap on Liquid Glass, then...
m4 macbook air blue

M5 MacBook Air Coming Spring 2026 With M5 Mac Studio and Mac Mini in Development

Thursday October 16, 2025 3:57 pm PDT by
Apple plans to launch MacBook Air models equipped with the new M5 chip in spring 2026, according to Bloomberg's Mark Gurman. Apple is also working on M5 Pro and M5 Max MacBook Pro models that will come early in the year. Neither the MacBook Pro models nor the MacBook Air models are expected to get design changes, with Apple focusing on simple chip upgrades. In the case of the MacBook Pro, a m...

Top Rated Comments

lkrupp Avatar
109 months ago
So many betas nowadays :)
Waiting for 10.13 DP 2
I guess there’s no middle ground. Some are always screaming, “Doesn’t Apple test this stuff before they release it.” “Apple’s QA is in the toilet these days” “Steve would never have allowed this.” Now we’re starting hear, “Too many betas.” “Too confusing.” “Take my hand and show me ,step by step, how to back out of this POS beta.” Apple can’t win.
[doublepost=1497378192][/doublepost]
Seems like a cheap way to crowd source bug spotting. The only problem I fear is that internal QC/QA has been cut in response. Some things like security really need to be done right the first time.
See what I mean?
Score: 9 Votes (Like | Disagree)
asiga Avatar
109 months ago
When this goes final, I wonder if this will be the time to upgrade from El Capitan on my daily driver? I don't usually wait so long, but almost all of the new features in Sierra don't apply to me.
After bad experiences from updating soon these last years, I decided to update only once per year, in summer, when they release the last update for the current MacOS. It's somewhat drastic, but it works great for me, as it lets me work with the same level of stability I was used to in the 10.4.x - 10.6.x years. So, yes, I'm updating to Sierra when 10.12.6 gets final.
Score: 4 Votes (Like | Disagree)
kalakana Avatar
109 months ago
I think high Sierra will just be super stable.
cough...brand new file system, what can go wrong...cough
Score: 3 Votes (Like | Disagree)
manhattanboy Avatar
109 months ago
So many betas nowadays :)
Seems like a cheap way to crowd source bug spotting. The only problem I fear is that internal QC/QA has been cut in response. Some things like security really need to be done right the first time.
Score: 2 Votes (Like | Disagree)
CristianM Avatar
109 months ago
I guess there’s no middle ground. Some are always screaming, “Doesn’t Apple test this stuff before they release it.” “Apple’s QA is in the toilet these days” “Steve would never have allowed this.” Now we’re starting hear, “Too many betas.” “Too confusing.” “Take my hand and show me ,step by step, how to back out of this POS beta.” Apple can’t win.
[doublepost=1497378192][/doublepost]

See what I mean?
Apple keeps hiking the prices of their already expensive computers. At that peice, a user should not be expected to test out buggy beta software for a few months and has every right to expect that everything should work perfectly - that's what we pay all that cash for right?
Score: 1 Votes (Like | Disagree)
ncollingridge Avatar
109 months ago
I'm still waiting to hear that PDFKit has been fixed before upgrading to Sierra. Why the total radio silence on this issue from all directions?
Score: 1 Votes (Like | Disagree)