Finding specific things

Clearing out old installers

Updated 2026-07-31 · 3 min read

Every app you ever installed left an installer behind. They are among the easiest gigabytes to reclaim, and among the most commonly forgotten.

Find them everywhere, largest first

find ~ \( -name "*.dmg" -o -name "*.pkg" -o -name "*.iso" \) -type f 2>/dev/null   -exec du -sh {} \; | sort -hr | head -30

Only the old ones

find ~ \( -name "*.dmg" -o -name "*.pkg" \) -type f -mtime +180 2>/dev/null

Anything you downloaded six months ago and have not touched is almost certainly installed already, or abandoned.

Why they are safe to delete

A .dmg is a disk image containing the app — once the app is in /Applications, the image is redundant. A .pkg is an installer script; the same applies. Both can be downloaded again from the vendor.

The exceptions worth keeping: installers for apps no longer sold, licensed versions you cannot re-download, and anything where the vendor has since gone out of business.

Do not forget mounted images

An old .dmg can still be mounted and quietly holding a volume open:

hdiutil info | grep "image-path"

Eject anything you no longer need before deleting the file.

Making this a habit

The reason these accumulate is that nothing surfaces them. A saved search for ext:dmg | ext:pkg — or the same idea as a Finder Smart Folder — turns an annual cleanup into a glance.

Common questions

Can I delete a .dmg after installing the app?

Yes. The app in /Applications is a complete copy; the disk image is only the delivery mechanism.

What is the difference between .dmg and .pkg?

A .dmg is a mountable disk image you drag from. A .pkg runs an installer that places files itself.