macOS Install & setup

Upgrade macOS safely (backup first)

Major macOS upgrades go smoothly when backups and disk space are sorted first.

14 min read Beginner Updated 9 Jun 2026

Step-by-step guide

Work through each section in order. Stop when your issue is resolved — you do not need every step for every situation.

Warning

Create a Time Machine backup before major updates, disk operations, or security changes on macOS.

What you will achieve

Major macOS upgrades go smoothly when backups and disk space are sorted first.

1) Pre-upgrade checks (Ventura/Sonoma+)

  1. Open System Settings → General → Software Update and note the target version.
  2. Confirm at least 30 GB free in System Settings → General → Storage.
  3. Run a full Time Machine backup and verify latest snapshot completed.

2) Start upgrade from Software Update

  1. Plug into power and stable Wi-Fi/Ethernet.
  2. Choose Upgrade Now and avoid forced shutdown during black-screen phases.

3) Post-upgrade validation

  • Check app compatibility and login items.
  • Confirm iCloud sync and FileVault status.

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macos time machine upgrade