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
77 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
77 months ago
So glad I am skipping Catalina. What an embarrassment.
Score: 4 Votes (Like | Disagree)
globalmatt Avatar
77 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)
Mightee Avatar
77 months ago
Do iMacs sleep now?
Score: 3 Votes (Like | Disagree)
orbital~debris Avatar
77 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)
ruslansv Avatar
77 months ago

10.16 betas will be here within 5 months.
So we can get new bugs in addition to all of the existing ones
Score: 2 Votes (Like | Disagree)

Popular Stories

New Intel Logo

Apple and Intel Rumored to Partner on Mac Chips Again in a New Way

Friday November 28, 2025 7:33 am PST by
While all Macs are now powered by Apple's custom-designed chips, a new rumor claims that Apple may rekindle its partnership with Intel, albeit in a new and limited way. Apple supply chain analyst Ming-Chi Kuo today said Intel is expected to begin shipping Apple's lowest-end M-series chip as early as mid-2027. Kuo said Apple plans to utilize Intel's 18A process, which is the "earliest...
iPhone Pocket Short

iPhone Pocket is Now Completely Sold Out Worldwide

Tuesday November 25, 2025 7:16 am PST by
Apple recently teamed up with Japanese fashion brand ISSEY MIYAKE to create the iPhone Pocket, a limited-edition knitted accessory designed to carry an iPhone. However, it is now completely sold out in all countries where it was released. iPhone Pocket became available to order on Apple's online store starting Friday, November 14, in the United States, France, China, Italy, Japan, Singapore, ...
iphone black friday gold

The Best Black Friday iPhone Deals Still Available

Friday November 28, 2025 6:24 am PST by
Cellular carriers have always offered big savings on the newest iPhone models during the holidays, and Black Friday 2025 sales have kicked off at AT&T, Verizon, T-Mobile, and more. Right now we're tracking notable offers on the iPhone 17, iPhone 17 Pro, iPhone 17 Pro Max, and iPhone Air. For even more savings, keep an eye on older models during the holiday shopping season. Note: MacRumors is...
apple store down feature

Here's Why the Apple Store is Going Down

Thursday November 27, 2025 1:01 pm PST by
Apple's online store is going down for a few hours on a rolling country-by-country basis right now, but do not get your hopes up for new products. Apple takes its online store down for a few hours ahead of Black Friday every year to tease/prepare for its annual gift card offer with the purchase of select products. The store already went down and came back online in Australia and New Zealand, ...
streaming black friday 2025

Best Black Friday Streaming Deals - Save Big on Apple TV, Disney+, Hulu, and More

Thursday November 27, 2025 1:14 pm PST by
We've been focusing on deals on physical products over the past few weeks, but Black Friday is also a great time of year to purchase a streaming membership. Some of the biggest services have great discounts for new and select returning members this week, including Apple TV, Disney+, Hulu, Paramount+, Peacock, and more. Note: MacRumors is an affiliate partner with some of these vendors. When...
iphone air camera

iPhone Air Flop Sparks Industry Retreat From Ultra-Thin Phones

Thursday November 27, 2025 3:14 am PST by
Apple's disappointing iPhone Air sales are causing major Chinese mobile vendors to scrap or freeze their own ultra-thin phone projects, according to reports coming out of Asia. Since the ‌iPhone Air‌ launched in September, there have been reports of poor sales and manufacturing cuts, while Apple's supply chain has scaled back shipments and production. Apple supplier Foxconn has...
maxresdefault

The MacRumors Show: Apple's Big Plans for iPad Mini 8

Friday November 28, 2025 8:39 am PST by
On this week's episode of The MacRumors Show, we talk through the latest rumors about Apple's upcoming iPad mini 8. Subscribe to The MacRumors Show YouTube channel for more videos The next-generation version of the iPad mini is expected to feature an OLED display, as part of Apple's plan to expand the display technology across many more of its devices. Apple's first OLED device was the Apple...
Apple Foldable Thumb

Foldable iPhone to Debut These Three Breakthrough Features

Tuesday November 25, 2025 7:09 am PST by
Apple's first foldable iPhone is expected to launch alongside the iPhone 18 Pro models in fall 2026, and it's shaping up to include three standout features that could set it apart from the competition. The book-style foldable will reportedly feature an industry-first 24-megapixel under-display camera built into the inner display, according to a recent JP Morgan equity research report. That...