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

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

Apple today seeded the fifth beta of an upcoming macOS Sierra update to developers and public beta testers, just over one week after seeding the fourth beta and a month after releasing the new macOS Sierra operating system to the public.

macOS Sierra 10.12.1 beta 5 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.

sierra10121beta
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 four betas, but it 10.12.1 does include Photos support for the new iPhone 7 Plus Portrait feature introduced with iOS 10.1. New features discovered in the fifth 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

macOS 27 on MacBook Pro

Apple Says macOS 27 Won't Be Compatible With These Macs

Wednesday June 3, 2026 8:29 am PDT by
During WWDC 2025, Apple revealed that macOS 26 Tahoe would be the final major macOS version for Intel-based Macs. macOS 27 will be compatible with Apple silicon Macs only, meaning that you will need a Mac with an M-series chip or a MacBook Neo with an A18 Pro chip in order to install the software update. Apple will unveil macOS 27 during its WWDC 2026 keynote this Monday, June 8, and the...
MacBook Neo on Yellow Feature

MacBook Neo is So Popular That Apple Reportedly Doubled Production

Wednesday June 3, 2026 9:24 am PDT by
On an earnings call in late April, Apple's CEO Tim Cook said that customer response to the MacBook Neo was "off the charts," and the popularity of the laptop has reportedly led the company to significantly boost production. Apple supply chain analyst Ming-Chi Kuo this week said he believes that MacBook Neo shipments to Apple were doubled from an initial target of 5 million units to 10...
iphone 18 pro blue%402x

iPhone 18 Pro: Dark Cherry, Light Blue, and Dark Gray Chassis Leaked [Update]

Thursday June 4, 2026 5:18 am PDT by
Update: Since publication, new information has come to light suggesting the images have been AI-manipulated and are not in fact iPhone 18 Pro chassis parts. The original article follows. The color options Apple is reportedly planning for the upcoming iPhone 18 Pro and ‌iPhone 18 Pro‌ Max have appeared online today in the form of images of chassis parts of unknown authenticity....

Top Rated Comments

Dydegu Avatar
126 months ago


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 ('https://www.macrumors.com/2016/09/28/late-october-macbook-pro/') set to be released later this year.
Don't even give them the option. Change that to next week.
Score: 9 Votes (Like | Disagree)
126 months ago
For the love of god please fix the issue with external 4K monitors (Dell P2415Q in my case) not turning on when connected to a closed rMBP on a restart and then not allowing the built in screen to turn on when opening it, causing a hard reboot with the screen open. Worked great in all versions of El Capitan..
Absolutely agree. Asus here, same problem.
And not just that:

* flickering screen,
* buggy video controls,
* sudden resets,
* BEACHBALLS,
* software that stopped for working (for no apparent reason),
* slow behaviour,
* iTunes before that was way snappier (don't get me started on the stupid hearts-system where one state cannot be accessed in playlists).
* iTunes Backups from iPhone cannot be saved "no disk space" (with 230GB available),
* Word cannot save temporary files anymore - and crashes,
* Bluetooth automatically disconnects - reconnects - disconnects.
* Cannot use the Apple Watch to unlock, as I have several iPads, including an old one which will stop working once I activate two-way authentification...
* losing WiFi
* Safari cannot open webpages (Firefox can)
* Lightroom crashes when converting to DNG


... all of this worked with Mavericks and stopped with Sierra. Thank you, Apple.

The list is so long, I have regretted updating my system and I will certainly never ever again update my computer, once the last service update has come along.
Sierra has been a disappointment all along.

Phew...

Has Apple forgotten that people actually work with this OS and depend on its reliability. Have they forgotten that this was the reason we chose to invest money?

I love Apple. I hate what it has become.
Score: 7 Votes (Like | Disagree)
otternonsense Avatar
126 months ago
I hope they've fixed all the Safari bugs and glitches.
Score: 7 Votes (Like | Disagree)
meaning-matters Avatar
126 months ago
Picture doesn't look like invitation; not interested.
Score: 5 Votes (Like | Disagree)
justperry Avatar
126 months ago
My ipad is not finding the update. I got Beta 4 the other day but it says up to date now. I even restarted it. Did the ipad not get Beta 5?
Haha, this is MacOS.:p
Score: 4 Votes (Like | Disagree)
CheesePuff Avatar
126 months ago
For the love of god please fix the issue with external 4K monitors (Dell P2415Q in my case) not turning on when connected to a closed rMBP on a restart and then not allowing the built in screen to turn on when opening it, causing a hard reboot with the screen open. Worked great in all versions of El Capitan..
Score: 4 Votes (Like | Disagree)