Apple Seeds Second Beta of Upcoming macOS Catalina 10.15.3 Update to Developers [Update: Public Beta Available] - MacRumors
Skip to Content

Apple Seeds Second Beta of Upcoming macOS Catalina 10.15.3 Update to Developers [Update: Public Beta Available]

by

Apple today seeded the second beta of an upcoming macOS 10.15.3 update to developers for testing purposes, nearly a month after seeding the first beta and over a month after releasing the macOS Catalina 10.15.2 update.

The new ‌‌macOS Catalina‌‌ beta can be downloaded using the Software Update mechanism in System Preferences after installing the proper software from the Developer Center.

macos catalina wallpaper
We don't yet know what improvements the third update to macOS Catalina will bring, but it will likely focus on performance improvements, security updates, and fixes for bugs that weren't able to be fixed in the macOS Catalina 10.15.2 update.

macOS Catalina 10.15.3 has code in it that suggests a new "Pro Mode" is coming to Apple's Macs. Pro Mode appears to be an optional setting that overrides fan speed limits and energy saving restrictions to improve performance. The code says that apps "may run faster" but battery life could decrease and fan noise could increase.

It's not entirely clear if Pro Mode is coming to Macs in the 10.15.3 release, but the code is there so it is a possibility.

We didn't find any other new changes in the first beta of macOS Catalina 10.15.3, but we'll update this post if there's anything new in the second beta.

Related Forum: macOS Catalina

Top Rated Comments

orbital~debris Avatar
89 months ago
Hopefully the delay is because Apple have focussed on eliminating the email data loss bug(s).
Still waiting to upgrade to Catalina…
Score: 6 Votes (Like | Disagree)
BWhaler Avatar
89 months ago
So glad I am skipping Catalina. What an embarrassment.
Score: 4 Votes (Like | Disagree)
orbital~debris Avatar
89 months ago

MR can you please combine your “Apple Seeds Beta X” news stories for all the devices?

Your front page with a wall of these for each product is a bit silly.
Hmm… do you see them all on the front page?

I was going to comment that I'd like to see the macOS (and watchOS & tvOS) beta news items in the main column instead of the 'Page 2' sidebar. Especially the macOS ones, since this is MacRumours, after all.

Separating them is good, as it allows a relevant discussion thread per news item. (And that would be another reason to have the macOS item appear in the main page - it might generate more views and more comments in the linked thread.)
Score: 3 Votes (Like | Disagree)
89 months ago

Hopefully the delay is because Apple have focussed on eliminating the email data loss bug(s).
Still waiting to upgrade to Catalina…
I’m really hoping this too. Currently using Thunderbird on Catalina for this reason. It’s not as nice to use as Apple Mail, but at least it doesn’t silently delete my emails.
Score: 3 Votes (Like | Disagree)
89 months ago
Do iMacs sleep now?
Score: 3 Votes (Like | Disagree)
89 months ago
Here's an interesting change... They made the Mac's Display in the "Display" system preference have a text window open titled "Think Different" and the text is of the Think Different mantra. Nice Apple!

Attachment Image
Score: 2 Votes (Like | Disagree)

Popular Stories

iPhone Duo Display Cracking

Apple Alerts Stores to iPhone Duo's Display Cracking Issue

Friday October 30, 2026 3:20 pm PDT by
In a memo shared with Apple Stores and Apple Authorized Service Providers this week, and later obtained by MacRumors, Apple provided technicians with guidance on how to diagnose and address the iPhone Duo's inner display cracking issue. If a customer reports the issue, Apple advised technicians to inspect the iPhone Duo and repair or replace it in accordance with their standard procedures....
apple pro tell logo

Apple Launching Five New Products This Friday

Monday November 2, 2026 1:22 am PST by
Apple is releasing five new products this Friday, November 6, following pre-orders that opened last week, including its first touchscreen MacBook Pro models. The following new products will be available from Friday: iPad mini with OLED display and A20 Pro chip iMac with M6 chip 14-inch MacBook Pro with M6 chip 14-inch MacBook Pro with OLED touchscreen 16-inch MacBook Pro with OLED...
Everything New Your iPhone Can Do on iOS 27

14 New Things Your iPhone Can Do in iOS 27.2

Friday October 30, 2026 12:42 pm PDT by
Apple released iOS 27.2 on October 26, bringing enhancements to Siri AI, adding Suggestions in Messages, and sneaking in a string of smaller additions across Photos, Podcasts, Games, Apple TV, and FaceTime. iOS 27.2 is available to download to your device now via Settings ➝ General ➝ Software Update. Note that some features may not be available in all regions or on all iPhone models....
Latest Stories
John Ternus Hosting His First Earnings Call as Apple CEO Today
John Ternus Hosting His First Earnings Call as Apple CEO Today
57 minutes ago
Here's What Spotify Looks Like on Apple's HomeView
Here's What Spotify Looks Like on Apple's HomeView
2 hours ago
iOS 27.2.1 Coming Soon, iOS 27.3 Beta Likely Available Tomorrow
iOS 27.2.1 Coming Soon, iOS 27.3 Beta Likely Available Tomorrow
2 hours ago
Mark Gurman: Apple Initially Aimed to Release iPhone Duo in November
Mark Gurman: Apple Initially Aimed to Release iPhone Duo in November
3 hours ago
Best Early Black Friday Deals on Apple Products Available Now
Best Early Black Friday Deals on Apple Products Available Now
3 hours ago
Apple Isn't Done With 2026: Here's What's Still Coming
Apple Isn't Done With 2026: Here's What's Still Coming
3 hours ago
Apple 'HomeView Ultra' With 9-Inch 360º Screen Detailed in New Report
Apple 'HomeView Ultra' With 9-Inch 360º Screen Detailed in New Report
3 hours ago
Apple TV 4K Pre-Order Discount Returns at Amazon
Apple TV 4K Pre-Order Discount Returns at Amazon
4 hours ago
Zoom and These Microsoft Apps Now Optimized for iPhone Duo
Zoom and These Microsoft Apps Now Optimized for iPhone Duo
4 hours ago
Canva Brings Free All-in-One Affinity App to iPad
Canva Brings Free All-in-One Affinity App to iPad
5 hours ago
iPhone Duo: Latest Buyer Wait Times
iPhone Duo: Latest Buyer Wait Times
6 hours ago
iPhone Duo Owners Can't Change Display Zoom After Setup
iPhone Duo Owners Can't Change Display Zoom After Setup
2 hours ago
Apple HomeView Could Double as a Security Camera
Apple HomeView Could Double as a Security Camera
9 hours ago
Apple Launching Five New Products This Friday
Apple Launching Five New Products This Friday
9 hours ago
Nearly Every M5 MacBook Air Now $200 Off on Amazon
Nearly Every M5 MacBook Air Now $200 Off on Amazon
1 day ago
Apple's HomeView Ships With Six-Month-Old Software
Apple's HomeView Ships With Six-Month-Old Software
1 day ago
Three New iPads Rumored to Launch in First Half of 2027
Three New iPads Rumored to Launch in First Half of 2027
1 day ago
Apple Offers Steps to Fix Daylight Saving Time Bug on Apple Watch
Apple Offers Steps to Fix Daylight Saving Time Bug on Apple Watch
1 day ago
Apple Watch Ultra 4 Hits All-Time Low Price With Amazon's $99 Discount
Apple Watch Ultra 4 Hits All-Time Low Price With Amazon's $99 Discount
2 days ago
Reminder: Apple's Big Discount on Beats 360 Ear Cushions Ends Today
Reminder: Apple's Big Discount on Beats 360 Ear Cushions Ends Today
2 days ago
Here's a New Tour of Apple's HomeView Software
Here's a New Tour of Apple's HomeView Software
2 days ago
Apple Reveals New iPad Mini's Battery Capacity
Apple Reveals New iPad Mini's Battery Capacity
2 days ago
Top Stories: Apple's Big MacBook Pro, iPad mini and iMac Updates
Top Stories: Apple's Big MacBook Pro, iPad mini and iMac Updates
2 days ago
'Pluribus' Season 2 Reportedly Starts Production Today
'Pluribus' Season 2 Reportedly Starts Production Today
2 days ago
iPhone 18 Pro Sales Surge in China, Offsetting Decline in U.S. and Japan
iPhone 18 Pro Sales Surge in China, Offsetting Decline in U.S. and Japan
3 days ago
HomeView Software 27.2: Wallpapers, Control Center, and More
HomeView Software 27.2: Wallpapers, Control Center, and More
3 days ago
Apple Alerts Stores to iPhone Duo's Display Cracking Issue
Apple Alerts Stores to iPhone Duo's Display Cracking Issue
3 days ago
iOS 27.3 Will Enable These Apple Intelligence Features in China
iOS 27.3 Will Enable These Apple Intelligence Features in China
3 days ago
Apple Says iOS 27.3 Beta Coming Next Week
Apple Says iOS 27.3 Beta Coming Next Week
3 days ago
Apple's Flash Storage Suppliers Are Finally 'Getting Their Revenge'
Apple's Flash Storage Suppliers Are Finally 'Getting Their Revenge'
3 days ago