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
69 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
69 months ago
So glad I am skipping Catalina. What an embarrassment.
Score: 4 Votes (Like | Disagree)
globalmatt Avatar
69 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
69 months ago
Do iMacs sleep now?
Score: 3 Votes (Like | Disagree)
orbital~debris Avatar
69 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
69 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

iphone 16 display

iPhone 17's Scratch Resistant Anti-Reflective Display Coating Canceled

Monday April 28, 2025 12:48 pm PDT by
Apple may have canceled the super scratch resistant anti-reflective display coating that it planned to use for the iPhone 17 Pro models, according to a source with reliable information that spoke to MacRumors. Last spring, Weibo leaker Instant Digital suggested Apple was working on a new anti-reflective display layer that was more scratch resistant than the Ceramic Shield. We haven't heard...
iPhone 17 Air Pastel Feature

iPhone 17 Reaches Key Milestone Ahead of Mass Production

Monday April 28, 2025 8:44 am PDT by
Apple has completed Engineering Validation Testing (EVT) for at least one iPhone 17 model, according to a paywalled preview of an upcoming DigiTimes report. iPhone 17 Air mockup based on rumored design The EVT stage involves Apple testing iPhone 17 prototypes to ensure the hardware works as expected. There are still DVT (Design Validation Test) and PVT (Production Validation Test) stages to...
Beyond iPhone 13 Better Blue

20th Anniversary iPhone Likely to Be Made in China Due to 'Extraordinarily Complex' Design

Monday April 28, 2025 4:29 am PDT by
Apple will likely manufacture its 20th anniversary iPhone models in China, despite broader efforts to shift production to India, according to Bloomberg's Mark Gurman. In 2027, Apple is planning a "major shake-up" for the iPhone lineup to mark two decades since the original model launched. Gurman's previous reporting indicates the company will introduce a foldable iPhone alongside a "bold"...
iphone 17 air iphone 16 pro

iPhone 17 Air USB-C Port May Have This Unusual Design Quirk

Wednesday April 30, 2025 3:59 am PDT by
Apple is preparing to launch a dramatically thinner iPhone this September, and if recent leaks are anything to go by, the so-called iPhone 17 Air could boast one of the most radical design shifts in recent years. iPhone 17 Air dummy model alongside iPhone 16 Pro (credit: AppleTrack) At just 5.5mm thick (excluding a slightly raised camera bump), the 6.6-inch iPhone 17 Air is expected to become ...
apple watch ultra yellow

What's Next for the Apple Watch Ultra 3 and Apple Watch SE 3

Friday April 25, 2025 2:44 pm PDT by
This week marks the 10th anniversary of the Apple Watch, which launched on April 24, 2015. Yesterday, we recapped features rumored for the Apple Watch Series 11, but since 2015, the Apple Watch has also branched out into the Apple Watch Ultra and the Apple Watch SE, so we thought we'd take a look at what's next for those product lines, too. 2025 Apple Watch Ultra 3 Apple didn't update the...
iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro Launching Later This Year With These 13 New Features

Wednesday April 23, 2025 8:31 am PDT by
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models as of April 2025: Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone ...
iPhone 17 Pro on Desk Feature

All iPhone 17 Models Again Rumored to Feature 12GB of RAM

Tuesday April 29, 2025 3:36 am PDT by
All upcoming iPhone 17 models will come equipped with 12GB of RAM to support Apple Intelligence, according to the Weibo-based leaker Digital Chat Station. The claim from the Chinese leaker, who has sources within Apple's supply chain, comes a few days after industry analyst Ming-Chi Kuo said that the iPhone 17 Air, iPhone 17 Pro, and iPhone 17 Pro Max will all be equipped with 12GB of RAM. ...
AirPods Pro 3 Mock Feature

AirPods Pro 3 Just Months Away – Here's What We Know

Tuesday April 29, 2025 1:30 am PDT by
Despite being more than two years old, Apple's AirPods Pro 2 still dominate the premium wireless‑earbud space, thanks to a potent mix of top‑tier audio, class‑leading noise cancellation, and Apple's habit of delivering major new features through software updates. With AirPods Pro 3 widely expected to arrive in 2025, prospective buyers now face a familiar dilemma: snap up the proven...