Open the App Store , click the Updates tab, and install all available updates to 10.13.6 to ensure a stable base.
Open your essential applications to check if they require updates to work in 64-bit mode.
Search for "macOS Catalina" in the App Store.
Secure 64-bit replacement variants or subscriptions before moving forward. how to update macos high sierra 10136 to 1015
Use the built-in Time Machine utility to back up your entire system to an external drive. This is critical as the upgrade may reformat your drive to the APFS file system.
Catalina introduces new privacy controls.
Once upon a time, in the land of Silicon Valley, there lived an old but reliable Mac running macOS High Sierra 10.13.6 Open the App Store , click the Updates
You need at least for the download and installation process.
Once the installer is downloaded (it’s about 8 GB), follow these steps.
Before proceeding, verify which of your critical apps are 32-bit: Hold the key and click the Apple menu (\apple). Select System Information . Catalina introduces new privacy controls
Once the download is complete, the installer will open automatically. Click and follow the on-screen instructions. Agree to the software license terms.
Look at the overview tab to see your exact model name and year (e.g., MacBook Pro (Retina, 15-inch, Mid 2014) ).
macOS Catalina drops support for several older Mac models that were capable of running High Sierra. Before attempting the installation, verify that your machine is officially supported. Supported Mac Models for macOS Catalina 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 or newer Mac Pro: Late 2013 or newer How to Check Your Mac Model Click the Apple icon in the top-left corner of your screen. Select About This Mac .