Apple Seeds Third Beta of macOS Catalina to Developers - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
Skip to Content

Apple Seeds Third Beta of macOS Catalina to Developers

Apple today seeded the third beta of macOS 10.15 Catalina for testing purposes, two weeks after seeding the second macOS Catalina beta and a month after the new Mac operating system update was first unveiled at the Worldwide Developers Conference.

The new macOS Catalina beta can be downloaded using the Software Update mechanism in System Preferences. As with all new betas, macOS Catalina should not be installed on a primary machine as it is early release software and could have major bugs.

test macOS 10
macOS Catalina removes the iTunes app, splitting it into Music, Podcasts, and TV apps. The Apple Music and Apple Podcasts apps are available now, while the Apple TV app is coming later this year.

The new apps are similar in function to iTunes, but are split up by feature. iOS device management is still available on the Mac, but it's now done through Finder rather than iTunes.

With a new Sidecar feature, you can turn your iPad into a second display for your Mac with just the click of a button. The Apple Pencil works with ‌Sidecar‌, so you can turn your ‌iPad‌ into a drawing tablet in apps like Photoshop and Illustrator.

Your Apple Watch can be used to approve security prompts in macOS Catalina, and Macs with a T2 chip support Activation Lock. There's a new Find My that brings the ‌Find My‌ Mac app to the Mac for the first time and even lets you track your devices when they're offline.

Screen Time is now available on the Mac as well as iOS devices, and Project Catalyst, a new Apple initiative, will let developers easily port their ‌iPad‌ apps over to the Mac.

There's a new Photos interface that surfaces your best photos organized by day, month, or year, there's a new start page in Safari, Mail has new tools for muting email threads and blocking senders, and the Reminders app has been overhauled.

32-bit apps no longer work in macOS Catalina, which is something to be aware of before installing the beta. For more details on macOS Catalina, make sure to check out our macOS Catalina roundup.

Related Forum: macOS Catalina

Popular Stories

Apple Event Logo

Apple Working on All-New Operating System

Wednesday July 29, 2026 11:39 am PDT by
Apple is developing an all-new operating system that is essentially a mix of tvOS, watchOS, and iOS, according to Bloomberg's Mark Gurman. In a report this week, he said the operating system will feature a grid of icons, widgets, and apps, along with customizable clock faces. The new software platform is intended for Apple's long-rumored smart home hub. With built-in facial recognition,...
imac video apple feature

Apple Made Its Second-Biggest Acquisition Ever This Year

Wednesday July 29, 2026 12:03 pm PDT by
Apple this year acquired Israeli startup Q.ai for close to $2 billion, according to the Financial Times. That would make this Apple's second-biggest acquisition ever, after it paid $3 billion for the popular headphone maker Beats in 2014. This is also the largest known Apple acquisition since the company purchased Intel's smartphone modem business and patents for $1 billion in 2019. Q.ai...
Four iPhone 18 Pro Colors Mock Feature

iPhone 18 Pro and iPhone Ultra: Pre-Orders and Release Date

Thursday July 30, 2026 6:12 am PDT by
Apple has yet to reveal when the iPhone 18 Pro and iPhone Ultra will be announced and released, but the dates usually follow a familiar pattern. Labor Day is September 7 this year. The last time the holiday fell on that day was in 2020, but the iPhone event that year was delayed until October due to the COVID-19 pandemic. So, the last time Labor Day was on September 7 in a normal year was in ...

Top Rated Comments

93 months ago
Ok, let me put it this way: Has ANYONE gotten this to install and if so, on what machine?
Score: 4 Votes (Like | Disagree)
93 months ago
If you are currently on Beta 2, 'softwareupdated' will install a bunch of packages to /Library/Updates/041-81733.

In this location there is 041-81733.en_GB.plist which has a line:

<bridge-version build-version="17.16.10496.5.4" build-group="0"/>

This fails to install for reasons mentioned earlier in this thread.

HOWEVER, if you re-install the Developer Beta Profile, it will instead download a larger set of packages to /Library/Updates/041-81731.

041-81731.en_GB.plist has an internal reference to build number 19A501i which is more recent than Beta2 which is 19A487i

The download finished and I am greeted with a functional installer Window...

EDIT: it is now installing just fine. Moral of the story: re-install the profile



Attachment Image
Score: 3 Votes (Like | Disagree)
embraceware Avatar
93 months ago
My bank has a 32-bit app that i want to use, so no upgrade for me. :(
One solution would be to setup a macOS Mojave install inside of Parallels Desktop or VMWare Fusion for 32-bit apps. Name it Rosetta ;).
Score: 3 Votes (Like | Disagree)
djchrisallen Avatar
93 months ago
What seems to have worked for me was going to Advanced from the Software Update pane, unchecking everything. The click Install Update again. This time no error and it went through
2019 15” MBP w TB, i9
This also just worked for me. Thanks for the tip.
Score: 2 Votes (Like | Disagree)
waquzy Avatar
93 months ago
Installed on MBP 2017 13” nTB

The beauty of the non Touch Bar MacBook Pro strikes again! (No offence to anyone)
Score: 2 Votes (Like | Disagree)
ian-frs Avatar
93 months ago
glad they tested this on new hardware before releasing...
Score: 2 Votes (Like | Disagree)

🔗 Related Apple News & Rumors

Stay updated with the latest Apple ecosystem news and verified rumors