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

Dynamic Island iPhone 18 Pro Feature

iPhone 18 Pro Prices Estimated Ahead of Apple Event Next Week

Thursday September 3, 2026 3:41 am PDT by
Less than a week before Apple debuts new iPhone 18 Pro models, research firm TrendForce has estimated the prices of the devices based on the latest hardware cost environment. TrendForce's price estimates compared to last year's models look like this: Model Starting Price Model Starting Price Change iPhone 17 Pro $1,099 iPhone 18 Pro $...
iPhone Handoff Feature

iOS 27 Introduces New 'iPhone Handoff' Feature

Wednesday September 2, 2026 12:35 pm PDT by
Apple has added a new "iPhone Handoff" feature to iOS 27 that will allow you to switch between two iPhones while using the same phone number on each device. This functionality was briefly mentioned during the WWDC 2026 keynote in June, on a slide that listed hundreds of new features coming in iOS 27 and corresponding software updates, but Apple never shared any further details at the time. ...
iPhone 18 Pro Dark Cherry Feature

iPhone 18 Pro Reportedly Starts With 256GB of Storage

Thursday September 3, 2026 9:22 am PDT by
While the iPhone 17 Pro has double the base storage compared to the iPhone 16 Pro, there will apparently be no further increase this year. Taiwanese research firm TrendForce today again reported that the iPhone 18 Pro models will start with 256GB of storage, like the iPhone 17 Pro models. Minimum storage capacities by model:iPhone 16 Pro: 128GB iPhone 17 Pro: 256GB iPhone 18 Pro...

Top Rated Comments

Dydegu Avatar
129 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)
129 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
129 months ago
I hope they've fixed all the Safari bugs and glitches.
Score: 7 Votes (Like | Disagree)
meaning-matters Avatar
129 months ago
Picture doesn't look like invitation; not interested.
Score: 5 Votes (Like | Disagree)
justperry Avatar
129 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
129 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)