Apple Seeds Fourth macOS Sierra 10.12.1 Beta to Developers and Public Beta Testers - MacRumors
Skip to Content

Apple Seeds Fourth macOS Sierra 10.12.1 Beta to Developers and Public Beta Testers

Apple today seeded the fourth beta of an upcoming macOS Sierra update to developers and public beta testers for testing purposes, one week after seeding the third beta and three weeks after releasing the new macOS Sierra operating system to the public.

macOS Sierra 10.12.1 beta 4 can be downloaded from the Apple Developer Center or through the Software update mechanism in the Mac App Store for those who already have an earlier 10.12.1 beta installed.

macossierra
macOS Sierra 10.12.1 appears to focus on bug fixes and under-the-hood performance improvements to address issues that have been found since the operating system's release, and it's also likely adding features designed for next-generation MacBook Pro models set to be released later this year.

Few outward-facing changes were discovered in the first three betas, but it does include Photos support for the new iPhone 7 Plus Portrait feature introduced with iOS 10.1. New features discovered in the fourth 10.12.1 beta will be listed below.

macOS Sierra is a significant update that brings features like Siri support, a new storage optimization option, cross device copy paste, auto unlocking with the Apple Watch, and more. For full details on macOS Sierra, make sure to check out our roundup.

Related Forum: macOS Sierra

Popular Stories

iPhone 18 Pro Deep Red Feature

iPhone 18 Pro Launching in Two Months With These 12 New Features

Friday July 17, 2026 10:39 am PDT by
It is now mid-July, and that means the iPhone 18 Pro and iPhone 18 Pro Max are now just two months away. The devices are expected to look similar to the iPhone 17 Pro and iPhone 17 Pro Max, but there will still be many year-over-year changes, with rumored features including a smaller Dynamic Island, 5G via satellite, and more. Apple is expected to unveil the iPhone 18 Pro, iPhone 18 Pro Max, ...
iPhone 18 Pro and Pro Max Feature

'Apple Upgrade' Program Reportedly Launching Next Week

Tuesday July 21, 2026 8:30 am PDT by
Apple and Klarna are partnering on a new "Apple Upgrade" program set to launch in the U.S. on Tuesday, July 28, according to Bloomberg's Mark Gurman. The program will allow you to finance most iPhone, iPad, Mac, and Apple Watch models, with a 24-month term for iPhones and Apple Watches and a 36-month term for iPads and Macs. Customers will be able to pay off the device early during the term, ...
iPhone 18 Pro Deep Red Feature

iPhone 18 Pro Launching in Two Months With These 12 New Features

Tuesday July 21, 2026 6:22 am PDT by
It is now mid-July, and that means the iPhone 18 Pro and iPhone 18 Pro Max are now just two months away. The devices are expected to look similar to the iPhone 17 Pro and iPhone 17 Pro Max, but there will still be many year-over-year changes, with rumored features including a smaller Dynamic Island, 5G via satellite, and more. Apple is expected to unveil the iPhone 18 Pro, iPhone 18 Pro Max, ...

Top Rated Comments

Jeremy1026 Avatar
128 months ago


macOS Sierra is a significant update that brings features like Siri support, a new storage optimization option, cross device copy paste, auto unlocking with the Apple Watch, and more. For full details on macOS Sierra, make sure to check out our roundup ('https://www.macrumors.com/roundup/macos-sierra/').
We get it.
Score: 25 Votes (Like | Disagree)
128 months ago
Remember when Apple used to make computers? So sad those days have passed. Been waiting a year for an updated MBP and will probably have to give up and buy a PC instead. Sad tears.
I mean, just wait a couple weeks. How bad do you need one? And why does it seem like everyone here needs a new Mac every 3 years? My 2007 MBP lasted all the way until 2013. I'm now using a 2013 rMBP, everything maxed out and I don't see myself buying a new Mac until at least 2020. What else could I possibly need?
Score: 17 Votes (Like | Disagree)
jmh600cbr Avatar
128 months ago
BRING ON THE MACS
Score: 9 Votes (Like | Disagree)
SamVilde Avatar
128 months ago
I mean, just wait a couple weeks. How bad do you need one? And why does it seem like everyone here needs a new Mac every 3 years? My 2007 MBP lasted all the way until 2013..
Oh, so you know exactly what it's like to be sitting here with an awesome much-loved 2008 MacBook, with its outdated and degraded screen, replacement battery barely able to hold an hour charge, refreshing the MacRumors feed because there's no way we're paying full price on an already-outdated upgrade a month before the launch of something better, and because after 8 years we really do deserve an improved machine in exchange for our frugality and patience. You know what it's like to be in this position.

How badly do I need one? I can wait a few weeks. I can wait a few months if I have to. But I don't feel like I'm being pathetic in wanting a replacement.
Score: 7 Votes (Like | Disagree)
ipodlover77 Avatar
128 months ago
Any hints towards the new macs?
Score: 7 Votes (Like | Disagree)
128 months ago
Any hints towards the new macs?
Once again, seeing the stock image used to illustrate these articles gave me a little flutter.

Followed by the depression upon realising its about the OS again. :(
Score: 6 Votes (Like | Disagree)