Certain third-party utilities are notorious for interfering with macOS upgrades. Before you begin, check for and uninstall any:
How to Update macOS High Sierra 10.13.6 to macOS Catalina 10.15
Your Mac will restart. The installation process usually takes 30 to 60 minutes. during this time. Troubleshooting & Alternative Paths how to update macos high sierra 10136 to 1015
macOS Catalina dropped support for older 32-bit graphics architectures. This means not every Mac capable of running High Sierra can upgrade to Catalina.
Check your current storage by going to > About This Mac > Storage . during this time
[High Sierra 10.13.6] ──> [Time Machine Backup] ──> [Download Catalina Installer via Safari] ──> [Run Setup] 1. Create a Time Machine Backup
Before 2026, the most important reason to upgrade is security. Running an outdated OS like High Sierra leaves your Mac vulnerable to known exploits. Furthermore, critical software like Google Chrome has ended support for High Sierra, meaning you won't receive essential security updates for your browser. By moving to Catalina (10.15), you regain access to crucial security updates for both the OS and your browser. Check your current storage by going to >
Catalina introduces a new file system (APFS) and a read-only system volume. If the upgrade fails, you need a backup.
Upgrading your Mac from macOS High Sierra (10.13.6) to macOS Catalina (10.15) introduces a more secure environment, modern app support, and features like Sidecar. However, jumping across two major generations of operating systems requires careful preparation.
macOS Catalina (10.15) requires specific hardware and 4GB of memory. Ensure your Mac is on the following list: : Early 2015 or newer MacBook Air : Mid 2012 or newer MacBook Pro : Mid 2012 or newer Mac mini : Late 2012 or newer iMac : Late 2012 or newer iMac Pro : 2017 models Mac Pro : Late 2013 or newer Step 2: Prepare for 64-bit Software
Your System Preferences will open to the Software Update panel, displaying a prompt to download macOS Catalina. Click .