How To Update Macos High Sierra 10.13.6 To 10.15 //top\\ May 2026

To update your Mac from macOS High Sierra 10.13.6 macOS Catalina 10.15

, you must first verify your hardware's compatibility and then manually download the installer via the App Store, as it won't appear in the standard "Software Update" window. Step 1: Check Compatibility

Not all Macs that run High Sierra can support Catalina. Ensure your model is on this list: : Early 2015 or newer MacBook Air : Mid 2012 or newer MacBook Pro : Mid 2012 or newer : Late 2012 or newer : Late 2012 or newer : 2017 or newer : Late 2013 or newer Apple Support Important Warning : macOS Catalina is the first version to drop support for 32-bit apps

. Check your critical apps for 64-bit compatibility before proceeding. Apple Support Community Step 2: Prepare Your Mac

how can I update mac os from High Sierra 10.13.6 version to 10.15? how to update macos high sierra 10.13.6 to 10.15

2.3 – Free Up Disk Space

The Catalina installer is about 8 GB, but it requires up to 20-25 GB of free space to unpack and install. You’ll need even more for smooth operation afterward.

Recommended free space: 30 GB minimum.

How to clean up High Sierra:

  • Empty Trash.
  • Use “Storage Management” (Apple menu → About This Mac → Storage → Manage).
  • Delete large old iOS backups (found in ~/Library/Application Support/MobileSync/Backup/).
  • Remove unused applications.
  • Use a tool like OmniDiskSweeper (free) to visualize space hogs.

Step 4: The Correct Upgrade Method (The "Apple Catalog" Trick)

To force the upgrade, you must download the full Catalina installer from Apple’s legacy server. To update your Mac from macOS High Sierra 10

  1. Open Safari (or Chrome/Firefox) on your High Sierra machine.
  2. Go to the official Apple Support page: https://support.apple.com/macos/catalina
    • Note: Apple hides this page. You may need to search "How to get old versions of macOS."
  3. Click the link for "macOS Catalina 10.15" – this will redirect to the Mac App Store.
  4. If the Mac App Store opens but says "Get," click it. If it says "Open," your download is already in /Applications.

Alternative (if the above fails): Use this direct link to the installer package (requires a fast internet connection): https://itunes.apple.com/us/app/macos-catalina/id1466841314?mt=12

5. Acquisition of macOS Catalina

Unlike minor updates, the installer for macOS Catalina is not always visible in the "Updates" tab of the Mac App Store on High Sierra machines. The most reliable method is using Apple’s official hidden support pages.

Technical Procedure: Upgrading from macOS High Sierra 10.13.6 to macOS Catalina 10.15

Date: October 26, 2023 Subject: System Upgrade Path and Migration Strategy Target Audience: Mac Users, System Administrators, and IT Support Staff

Quick checklist (before clicking Install)

  • [ ] Model confirmed compatible
  • [ ] Backup completed and verified
  • [ ] ≥30 GB free space
  • [ ] Critical apps compatible or updated
  • [ ] Power connected / stable internet

If you want, I can:

  • Provide the exact Apple support link for Catalina download,
  • Create Terminal commands for verifying free disk space and listing 32-bit apps,
  • Or give model-specific compatibility confirmation if you tell me your Mac model/year.

Dealing with 32-bit Apps

When you open an old 32-bit app, Catalina will show: “The application X needs to be updated.” There is no workaround. You must find a 64-bit replacement or keep High Sierra in a separate partition.

Step 3: Get the macOS Catalina installer

Since you are on High Sierra, the official method is via the App Store:

  1. Open App Store (or click Apple logo → About This Mac → Software Update).
  2. Search for “macOS Catalina”.
  3. Click Get or Download. (The installer is ~8 GB)
  4. The download will appear in your Applications folder as “Install macOS Catalina”.

If you cannot find Catalina: Apple sometimes hides older OS versions. Use this direct App Store link:
https://apps.apple.com/us/app/macos-catalina/id1466841314?mt=12

The "Should You?" Verdict

Do the upgrade IF:

  • You need a modern web browser (Chrome/Edge no longer support High Sierra).
  • You want access to newer versions of Adobe Creative Cloud or Microsoft 365.
  • You have an SSD (Solid State Drive). Catalina runs terribly on old spinning hard drives.

Do NOT do the upgrade IF:

  • You rely on legacy 32-bit software (e.g., older Adobe CS6, Office 2011, Steam games from 2014).
  • Your Mac is a 2011 or early 2012 model without a Metal GPU.
  • You have a mechanical HDD (Catalina will be painfully slow).