Where to find Mac OS Catalina .dmg file?

Question

Level 1

4 points

Where to find Mac OS Catalina .dmg file?

Hi! I'm trying to find the .dmg file for Catalina (10.15.7). I'm running a late 2012 iMac and Catalina is as far as I can go. It was running nicely, but I had to reset the system to create a fusion drive. I thought that Catalina would simply install itself in the new partition, but I obviously thought wrong and got downgraded back to Mountain Lion.

I found a .dmg file for Catalina from some random source, but Mountain Lion can't upgrade straight to Catalina. I got the .dmg file for Sierra with the following link:

How to download and install macOS - Apple Support

I installed Sierra and hoped to be able install Catalina with the file I had, but it was somehow a damaged file. I tried to download Catalina through the App Store, but to no avail. There is a page for Catalina on the App Store, but no download button available. I'm running the App store in German, and where it's supposed to say "Download" or "Install" or what not, it just says "Öffnen", but it's just a cosmetic element with no function.

Is there a functioning .dmg file for Catalina anywhere? I know it's already quite old, but most all of the apps I need work well with it and it would be a shame to have to get a different device, as I'm quite happy with the iMac itself. Thanks in advance.

Posted on Nov 21, 2024 8:25 PM

Reply

Answer 1

HWTech

Level 9

60,566 points

Nov 22, 2024 8:00 AM in response to LordNasahan

Apple never released a full macOS Catalina installer in DMG format. Apple only ever released minor Catalina update patches in DMG form and those require macOS Catalina to already be installed.

Here is an Apple article with links to various full macOS installers including Catalina:

How to download and install macOS - Apple Support

Theoretically if you boot into Internet Recovery Mode using Command + Option + R, then you should be able to access the most recent macOS online installer that is compatible with your Mac. Unfortunately some Macs may still boot to the online installer for the older OS that originally shipped with the Mac from the factory regardless of the keys used for booting.

Do you have access to another Mac from 2012 to mid-2020? If so, then you can use that Mac to download the Catalina installer and/or create a bootable macOS Catalina USB installer.

Reply

Answer 2

BDAqua

Level 10

245,405 points

Nov 21, 2024 8:44 PM in response to LordNasahan

On the "damaged" file, it may not reaslly be...

Disconnect from the Internet & set the Date back to 2014, then you can run the Install MacsOS ******* App in Applications, so expired Certificates are not expired.

Reply