Apple today released macOS Catalina 10.15.3, the third update to the macOS Catalina operating system that was released in October. macOS Catalina 10.15.3 comes over a month after the release of macOS Catalina 10.15.2.

‌‌macOS Catalina‌‌ 10.15.3 can be downloaded from the Mac App Store for free using the Update feature in the System Preferences app, and it is available to anyone who has a compatible Mac.

macos catalina wallpaper
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. According to Apple's release notes, the update includes Pro Display XDR optimizations and multi-stream video editing improvements.

The macOS Catalina 10.15.3 update improves the stability, reliability and security of your Mac, and is recommended for all users.
This update:
- Optimizes gamma handling of low gray levels on Pro Display XDR for SDR workflows when using macOS
- Improves multi-stream video editing performance for HEVC and H.264 encoded 4K video on the 16-inch MacBook Pro (2019)

For more on everything that's new in ‌macOS Catalina‌, make sure to check out our dedicated macOS Catalina roundup.

Related Forum: macOS Catalina

Top Rated Comments

sugargliderdude Avatar
sugargliderdude
79 months ago
i said i would install Catalina once its at 10.15.3 but still not sure if i should... hearing so many horror stories.
Score: 10 Votes (Like | Disagree)
jb-net Avatar
jb-net
79 months ago
Biggest question: Will it fix Mail's data loss bug? Or is Mail.app on Catalina still randomly deleting E-Mails?
Score: 8 Votes (Like | Disagree)
pavvel Avatar
pavvel
79 months ago

Fingers crossed for Notes syncing with iCloud again.
Never had a problem with notes syncing since the first version.
Score: 5 Votes (Like | Disagree)
VanNess Avatar
VanNess
79 months ago

I would switch the Apple Mail if it did one thing Outlook did. Separate days in my inbox. I have today, yesterday, last week and older in my main view in Outlook. Apple Mail is just here you go, sort it out.
You can set up smart mailboxes ('https://support.apple.com/guide/mail/use-smart-mailboxes-mlhlp1190/mac') for today, yesterday, last week, etc. Pretty easy to do and I have it set up that way with links copied to the favorites bar. Since they are smart mailboxes your inbox remains untouched. Since doing this I rarely access my inbox. No need.
Score: 5 Votes (Like | Disagree)
macintoshmac Avatar
macintoshmac
79 months ago

Biggest question: Will it fix Mail's data loss bug? Or is Mail.app on Catalina still randomly deleting E-Mails?
It was said to have been fixed in the third beta. If this build is the same or higher, the bug may be fixed. MR has stopped giving build numbers long back, so just wait for someone to provide you with a build number. I am downloading it, but did not bother to catch the build so can't tell you right now.
Score: 4 Votes (Like | Disagree)
Steve121178 Avatar
Steve121178
79 months ago

I just installed the update and the issue with the external monitor and the fans is still there, right now the fans are running at 3200 RPM and the machine is really hot just by browsing the web to get to this page.

I talked to Apple support (again) and now they want a video of the machine so they can hear the fans running, I can't believe that a company that just announced that made 92 billions in revenue in the last quarter can't replicate this issue on their offices. I'm starting to think that their priorities have changed
Not being funny, but you should know the Mac and macOS isn't a priority. The Mac has been severely neglected for many years and macOS gets a token annual update that doesn't really add very much and just further aligns the desktop OS with iOS in one way or another. There's been very little innovation and advancements with macOS.

The number of bugs and issues with Catalina is inexcusable, but do they really care? NO, they don't.

All the talent has been pulled from macOS over the years to work on iOS & it's variants as that is Apple's future. The Mac isn't.
Score: 4 Votes (Like | Disagree)
Read All Comments

Popular Stories

Aston Martin CarPlay Ultra Screen

Apple's CarPlay Ultra to Expand to These Vehicle Brands Later This Year

Sunday February 1, 2026 10:08 am PST by
Last year, Apple launched CarPlay Ultra, the long-awaited next-generation version of its CarPlay software system for vehicles. Nearly nine months later, CarPlay Ultra is still limited to Aston Martin's latest luxury vehicles, but that should change fairly soon. In May 2025, Apple said many other vehicle brands planned to offer CarPlay Ultra, including Hyundai, Kia, and Genesis. In his Powe...
Read Full Article • 88 comments
Apple Logo Black

Apple Just Made Its Second-Biggest Acquisition Ever After Beats

Thursday January 29, 2026 10:07 am PST by
Apple today confirmed to Reuters that it has acquired Q.ai, an Israeli startup that is working on artificial intelligence technology for audio. Apple paid close to $2 billion for Q.ai, according to sources cited by the Financial Times. That would make this Apple's second-biggest acquisition ever, after it paid $3 billion for the popular headphone and audio brand Beats in 2014. Q.ai has...
Read Full Article • 134 comments
Apple Logo Black

Apple's Next Launch is 'Imminent'

Sunday February 1, 2026 12:31 pm PST by
The calendar has turned to February, and a new report indicates that Apple's next product launch is "imminent," in the form of new MacBook Pro models. "All signs point to an imminent launch of next-generation MacBook Pros that retain the current form factor but deliver faster chips," Bloomberg's Mark Gurman said on Sunday. "I'm told the new models — code-named J714 and J716 — are slated...
Read Full Article
14 inch MacBook Pro Keyboard

Apple Changes How You Order a Mac

Saturday January 31, 2026 10:51 am PST by
Apple recently updated its online store with a new ordering process for Macs, including the MacBook Air, MacBook Pro, iMac, Mac mini, Mac Studio, and Mac Pro. There used to be a handful of standard configurations available for each Mac, but now you must configure a Mac entirely from scratch on a feature-by-feature basis. In other words, ordering a new Mac now works much like ordering an...
Read Full Article • 127 comments
Apple MacBook Pro M4 hero

New MacBook Pros Reportedly Launching Alongside macOS 26.3

Sunday February 1, 2026 5:42 am PST by
Apple is planning to launch new MacBook Pro models with M5 Pro and M5 Max chips alongside macOS 26.3, according to Bloomberg's Mark Gurman. "Apple's faster MacBook Pros are planned for the macOS 26.3 release cycle," wrote Gurman, in his Power On newsletter today. "I'm told the new models — code-named J714 and J716 — are slated for the macOS 26.3 software cycle, which runs from...
Read Full Article • 136 comments