Editing Openai/691c64c3-536c-8008-a507-c542c3a174f3 (section)

== gpt-5-1-thinking ==
=== User: how can i install macos 26.1 apps on external ssd? ===
how can i install macos 26.1 apps on external ssd?

=== Assistant: You can run apps from an external SSD on macOS 26.1, but there are some limits and a few different ways to do it. ===
You can run apps from an external SSD on macOS 26.1, but there are some limits and a few different ways to do it. Here’s the practical picture.

==== 0. What macOS allows / doesn’t allow ====
* You cannot globally tell macOS “install all apps to the external disk”.
* Mac App Store apps and most .pkg installers will always install to the internal system volume.
* Drag-and-drop apps (most .dmg apps with a single .app bundle) can live and run happily from an external SSD.
* You can also put a full macOS installation on the external SSD and install everything there.

So the method depends on the kind of app and how far you want to go.

==== 1. Easiest: Install drag-and-drop apps directly on the external SSD ====

Good for standalone apps (e.g. Firefox, LibreOffice, VLC, etc.), not from the App Store.
# Format the external SSD (if needed) - Open Disk Utility → View → Show All Devices. - Select the SSD → Erase… - Format: APFS - Scheme: GUID Partition Map - Name it e.g. ExternalSSD.
# Create an Applications folder on it - In Finder, open the SSD (e.g. ExternalSSD). - Create a folder called <code>Applications</code>.
# Install apps there - Open the app’s .dmg or installer. - Instead of dragging the app to /Applications, drag the .app to: - ExternalSSD/Applications/ - Optionally drag the app from that folder into the Dock.
# First launch (Gatekeeper) - First time you open it: Control-click → Open, then confirm. - After that, you can launch it normally.

: ✅ This saves internal SSD space, but note: the app’s settings, caches and support files still go to your internal disk in ~/Library and /Library.

==== 2. Full solution: Install macOS 26.1 itself on the external SSD ====

If you want everything (apps, libraries, system) on the external SSD, use it as a separate startup disk.

===== A. Prepare the external SSD =====
# Back up anything important on that SSD.
# Open Disk Utility.
# Select the external SSD device (top line, not its volume).
# Click Erase… - Format: APFS - Scheme: GUID Partition Map - Name: e.g. macOS-External.

===== B. Install macOS 26.1 to the SSD =====
# Open Install macOS 26.1 (from Applications or the App Store).
# When it asks where to install, click Show All Disks and choose macOS-External.
# Let the installation finish (the Mac will reboot a few times).

===== C. Boot from the external SSD =====

On Apple Silicon:
# Shut down the Mac.
# Press and hold the Power button until you see “Loading startup options”.
# Choose macOS-External.
# Click Continue.

Now, when you’re booted from the external system:
* All apps you install (App Store, .pkg, .dmg) will be on the external SSD’s system volume.
* Your internal macOS stays mostly untouched (good for testing or keeping it “clean”).

You can later set the default startup disk in
System Settings → General → Startup Disk.

==== 3. Advanced: Move a big non-App-Store app + use a symlink ====

This is only for advanced use and not recommended for App Store apps.

Example: you have a huge .app in /Applications you want to move.
# Quit the app.
# Move it to the external SSD, e.g.: ``<code>bash sudo mv "/Applications/BigApp.app" "/Volumes/ExternalSSD/Applications/BigApp.app" <syntaxhighlight>3. Create a symlink in /Applications: </syntaxhighlight>bash sudo ln -s "/Volumes/ExternalSSD/Applications/BigApp.app" "/Applications/BigApp.app" </code>``

macOS and Launchpad will still “see” it in /Applications, but the bytes live on the SSD.

⚠️ Caveats:
* Updates or installers may break or delete the symlink.
* Code signing / Gatekeeper can sometimes be picky.
* Don’t do this for system apps or App Store apps.

==== 4. What you can’t really move cleanly ====

Even if you put the .app on the SSD:
* App support data (~/Library/Application Support/...)
* Caches (~/Library/Caches/...)
* Preferences (~/Library/Preferences/...)

…will stay on your internal disk. That’s just how macOS is designed.

For Apple apps like Photos, Music, etc., the better move is:
* Keep the app internal (can’t move).
* Put the library (Photos Library, Music Library, etc.) on the external SSD and point the app there.

==== 5. Summary: what to actually do ====

If you just want to free some space and wear on the internal SSD:
* Put standalone non-App-Store apps in ExternalSSD/Applications.
* Move big libraries (Photos, Music, game libraries) to the SSD using each app’s settings.
* Leave macOS itself + App Store apps on the internal, unless you’re okay booting from the external disk.

If you tell me which specific apps you care about (e.g. Xcode, Steam, big games, etc.), I can give you a per-app recipe for using the external SSD as much as possible.