macOS Catalina 10.15 is the latest operating system that runs on Apple Mac laptops and desktops. However, it is still in beta test and only available for part of Mac computers with high profile or enrolled in Apple Beta Program. Is there any way to upgrade the macOS to Catalina manually or install Catalina on Mac from scratch? The answer is Yes. But you have to download macOS Cataina DMG or the installer app.

Changes introduced with macOS 10.15 (Catalina) cause certain Java applications to behave incorrectly. Therefore, we cannot certify any JDK version on macOS 10.15 yet. However, as of now, you can install and run non-notarized software on macOS 10.15 systems by modifying your security preferences. The easiest and most up to date method to install macOS Catalina in VMWare. I will update the link when 10.15.6 comes out later this year.Patreon: https://ww.

If you are looking for the easiest way to download macOS Catalina DMG on a Macand but don't know how? Well, there are three ways by which you can instantly get the latest macOS installer without a hassle.

Part 1. Get MacOS Catalina DMG Via Direct Download Link

Many people prefer the direct download link of macOS Catalina as it is more flexible. You can unpack the DMG file and make a bootable Catalina installer USB, which can be used to install macOS on other computers. However, it is not easy to find the direct download link because Apple wants you to upgrade from Mac App Store. Fortunately, there are a few good websites that host the direct download link of macOS Catalina DMG. After that, you can burn the macOS dmg to USB to make it bootable for installation.

macOS Catalina 10.15 DMG Download Link 1: https://themacgo.com/macdownload/ (Wait a few seconds and the download starts automatically.)

macOS Catalina 10.15 DMG Download Link 2: https://drive.google.com/drive/folders/1ELQXMuuVWddamLPG0RHjyvaNW4r628CM (Password: Geekrar.com)

macOS Catalina 10.15 DMG Download Link 3: http://www.mediafire.com/file/wazr84baudhi27h/macOS_Catalina_DMG_by_Geekrar.rar/file

macOS Catalina 10.15 DMG Download Link 4: https://sundryfiles.com/G54 (Premium account required for download!)

macOS Catalina 10.15 InstallESDDmg PKG Download Link : http://swcdn.apple.com/content/downloads/61/56/041-83630-A_8RCIBB415Y/7jqh3nh97ood2mjej7hdgpx7fgh5c3fi9g/InstallESDDmg.pkg

macOS Catalina 10.15 VMware Image Download Link: https://www.mediafire.com/file/yrd1py7od5911zt/Catalina_Virtual_Disk_Image_by_Techsviewer.rar/file

macOS Catalina 10.15 VirtualBox Image Download Link: https://www.mediafire.com/file/yrd1py7od5911zt/Catalina_Virtual_Disk_Image_by_Techsviewer.rar/file

Tips: After downloading macOS Catalina .dmg file, it is time to make a macOS bootable USB from it. For this purpose, you can give a try on UUByte DMG Editor, one of the most popular software to create a Catalina USB installer on both Windows PC and Mac.

Part 2. Download macOS Catalina From Mac App Store

Apple always recommends its users downloading macOS install file from Mac App Store for security reasons. It is safe and easy. But the actual downloaded file is not an dmg file. Instead, it is an app called Install macOS Catalina, which is used to make the upgrade from current macOS to Catalina. For a clean install, it is better to download the dmg file and make an installer USB.

Note: Make sure to back up your Mac prior to installing macOS Catalina.

Step 1: Go to Mac App Store and search macOS Catalina. Then hit on 'Get' to download page.

Step 2: Doing this will open System Preferences followed by the section of Software Update, where you will find MacOS Catalina ready to download. Hit the option saying 'Upgrade Now' and download MacOS Catalina on your Mac.

Step 3: Next, macOS Catalina upgrade will ask for system reboot. Complete the process and install macOS Catalina on that computer.

Downloading macOS Catalina Install app works fine on my of newly devices but it could be problems for old Macs even it is officially supported by Catalina. If this is the case, then you have to patch the OS and install Catalina again. However, you need find a third-party app to do the dirty work. We will talk about this in Part 3.

Part 3. Download macOS Catalina 10.15 Installer with macOS Catalina Patcher

Although it may appear easy to try out the conventional approach of downloading macOS update in Software Update, there are a few known issues on old Macs shipped in 2013 or earlier, meaning the download progress can not be completed successfully. That's why macOS Catalina Patcher tool comes into help. This patching tool makes the job even simpler for installing macOS Catalina on unsupported Mac models.

However, the file size of these updates differs depending on the Mac device you are using. That means the downloaded update might not necessarily be the full installer version. For instance, if you wish to keep the installer file as archive for further application, or use it to generate bootable flash drive, this file size won't be sufficient.

Fortunately, with macOS Catalina Patcher tool, you can simply download the entire update of macOS setup from Apple's servers. Let's check out the stepwise instructions of how to use this software tool to download the macOS Catalina DMG.

Step 1: Download a copy of macOS Catalina Patcher from this link.

Step 2: After downloading and attempting to install, an error notification will be prompted. It is due to the unavailability of developer verification credential for macOS. Now, go to System Preferences -> Security & Privacy. Then find the button saying 'Open Anyway' to let the app run.

Step 3: Open macOS Catalina Patcher app and from the main menu, navigate to Options to uncheck the box saying 'Auto-apply Post Install Patches'. As you are done with the previous step and move to the screen as in the link below, hit Download a Copy.

Macos 10.15 Install Brew

Step 4: The following screen will notify the file size of macOS Catalina you are to download. The resolution is around 7GB and after the download, it will automatically get stored in the Downloads folder. Then hit Continue to initiate the process of download.

Step 5: The download time of the file will depend upon the internet connection and its speed. So, you might have to wait for some while for the process to complete. Eventually, the entire macOS Catalina setup file will be available on your device.

Closing Words

Well, that is all for the day. Hopefully, the above methods were helpful in guiding you on how to download macOS Catalina for both supported and unsupported Macs. When the download is finished, the next step is to burn the DMG file to USB. Then boot macOS from USB and starts the installation wizard.

I purchased a used 2018 Mac mini desktop and wanted to put a fresh installation of the latest macOS 10.15 Catalina on it. Below are the steps I took.

Note: The instructions below are the same for macOS 10.13 High Sierra and macOS 10.14 Mojave.

Download macOS Catalina

You will need a Mac to download macOS Catalina; you can download Catalina from The Mac Go. (The Mac mini came with macOS 10.14 Mojave so I used it to download Catalina.)

Go to the Mac App Store, search for “macOS Catalina”, and download it. It will be saved to the “/Applications/Install macOS Catalina” location. If the installer automatically launches, just close it.

Note: If you plan to run the installer first to update your current macOS version to Catalina, you will want to move the “Install macOS Catalina” application out of the “/Applications” directory; otherwise, the installer will delete itself from the “/Applications” directory when the upgrade completes. For example, you can move the “Install macOS Catalina” application to the “~/Downloads” directory and run it from there.

Format USB Flash Drive

Because macOS Catalina is 8.4GB in size, you will need a 16GB USB flash drive. You don’t need to delete the existing content on the drive because we will blow it all away in a subsequent step.

If the USB flash drive is not already formatted as “Mac OS Extended (Journaled)”, format it like so:

1. Plug the USB flash drive into your Mac.
2. Launch the “Disk Utility” application.
3. On the left-hand pane, select the USB drive (not the partition under it, if any).
4. Click on the “Erase” tab (or button at the top).
   1. Input a name like “Catalina” (this name will be overwritten later).
   2. Select “Mac OS Extended (Journaled)” for “Format”.
   3. If available, select “Master Boot Record” for “Scheme”.
   4. Click the “Erase” button at the bottom. Click the “Erase” button in the warning popup dialog if you get one.
5. The format operation may take several minutes to complete. (USB 2.0 and large capacity drives may take longer.) After the format completes, the partition will be mounted under “/Volumes/Catalina” (or whatever name you selected above).
6. Close the “Disk Utility” application.

Macos 10.15 Install Java

Write macOS Catalina to USB Flash Drive

To create a bootable USB macOS Catalina installer, run the “Terminal” application and this command:

Note: If the createinstallmedia command returns a “Failed to start erase of disk due to error (-9999, 0)” error, then your current Mac OS X version does not fully support the createinstallmedia tool. Use a more recent macOS version (at least Mac OS X 10.11 El Capitan) or manually create the USB installation drive using instructions from Bootable USB Flash Drive to Install Mac OS X 10.10 Yosemite.

The “createinstallmedia” program will erase the USB flash drive, create a new partition named “Install macOS Catalina”, and copy the installation files to that partition. The output will look like:

The above process took 20-30 minutes using my Kingston USB 2.0 flash drive.

Boot From USB Flash Drive

Note: Apple’s How to create a bootable installer for macOS page suggest using the “Startup Disk” configuration (under “System Preferences”) to select the USB flash drive as the startup drive. Then on restart, the Mac should boot from the USB flash drive. Unfortunately, the “Startup Disk” did not list my USB flash drive as a startup option, so I was not able to use this method.

To boot a Mac with the USB flash drive:

1. Insert the USB flash drive.
2. While holding the “option” key down, turn on the Mac to display the Startup Manager.
3. You should see one or more icons, one of which should be called “Install macOS Catalina” for the USB flash drive. (The internal hard drive may not be visible if it does not have a valid, bootable partition installed.)
   • Note: If you don’t see the USB flash drive’s “Install macOS Catalina”, try removing and re-inserting the USB flash drive while viewing the Startup Manager screen. The USB flash drive should then appear after a few seconds.
4. Select the “Install macOS Catalina” (with left/right arrow keys) and hit the “return/enter” key to boot from the USB flash drive.

It may take 5-10 minutes to load the installer from the USB flash drive. Sometimes the progress bar may appear to be frozen or the screen will go black for a minute or two. Be patient.

External Startup Disk Not Allowed

On a newer Mac with the T2 security chip, booting from an external drive may be disallowed by default. Attempting to boot from a USB flash drive will result in a “Security settings do not allow this Mac to use an external startup disk” warning message.

To allow booting from the USB flash drive, do the following:

1. Hold down “Command-R” (hold down both the “Command ⌘” and “R” keys) when you start the Mac to launch macOS Recovery. You can release the keys when you see the Apple logo.
   • Tip: An easier alternative is to hold the “Option/Alt” key on boot to launch the Startup Manager. Then just click and release “Command-R” keys to launch macOS Recovery.
2. The macOS Recovery screen contains a top-level “macOS Utilities” menu.
3. Click on the “Utilities” menu and select “Startup Security Utility”. Input your administrator password when prompted.
4. In the Startup Security Utility, under “Allowed Boot Media”, select the “Allow booting from external or removable media” option.
5. If the Mac won’t have access to the Internet (either by wire or wirelessly) when installing macOS Catalina, make sure to select either the “Medium Security” or “No Security” option under the “Secure Boot” section. (You can change the option back to the default “Full Security” afterwards.)
6. Quit the macOS Utilities to restart the Mac.
7. On restart, follow the directions in the previous section to boot from the USB flash drive.

Erase the Internal Hard Drive

Macos 10.15 Install

When the installer finishes loading, you will see a “macOS Utilities” screen appear. It looks the same as the “macOS Recovery” screen with one difference. In the “macOS Utilities” window, the second option will say “Install macOS” instead of “Reinstall macOS”. In “macOS Recovery”, the “Reinstall macOS” option would just re-install the same version of macOS. The “Install macoS” option will install the macOS Catalina version on the USB flash drive.

Before installing macOS, I wanted a clean slate so I erased the internal hard drive like so:

1. Select the “Disk Utility” option and click the “Continue” button on the bottom to launch the “Disk Utility” application.
2. On the left-hand pane, select the internal hard drive (not the partition under it, if any).
3. Click on the “Erase” button at the top.
   1. Keep the default “Macintosh HD” name or input a new one.
   2. Select “APFS” for “Format”.
   3. Click the “Erase” button at the bottom. The SSD (Solid State Drive) format took less than a minute to complete.
4. Close the “Disk Utility” application.

Install macOS Catalina

Warning: If your Mac has a T2 security chip and you left the “Full Security” option configured in the Startup Security Utility, make sure that Internet access (wired or wireless) is available before starting the macOS Catalina installation. You can configure the wireless network by clicking on the wireless icon at the top-right corner of the macOS Utilities screen.

Back at the “macOS Utilities” window, do the following to start the macOS Catalina installation:

1. Click on the “Install macOS” option and click the “Continue” button.
2. The “macOS Catalina” installer’s splash screen will appear. Click the “Continue” button.
3. Click on the “Agree” button to agree to the license. A popup confirmation window will appear; click on the popup’s “Agree” button.
4. Select the internal hard drive and click the “Install” button.

My Mac mini took 20-30 minutes to complete the macOS Catalina installation. I think there were a couple of reboots in-between. And a few times, the screen would go black for a minute or two. Be patient and give the process an hour or more to complete.

If you run into problems installing macOS Catalina, check the “What Does Giving Up Mean?” section (at the bottom) of Install macOS Sierra Using Bootable USB Flash Drive for possible solutions.

Note: macOS Catalina seems to have an issue with my Dell 24in U2410 monitor. During the initial bootup screen, the monitor shows a blank screen with a message, “The current input timing is not supported by the monitor display”. Thankfully, the monitor works correctly after the bootup completes. And later, this warning message no longer appeared on bootup.

Enjoy your fresh installation of macOS 10.15 Catalina.