The short answer
Usually, after a check. Might hold something you care about. Look inside before removing it.
What is it?
Disk images and installers over 500 MB anywhere in your home folder outside Downloads and Library: .dmg, .iso, .img, .xip and .pkg files. They are often installers kept after installing, but can also be virtual machine disks, device images or encrypted volumes holding your own files.
Installers and disk images outside Downloads. Usually not needed once installed, but a .dmg can also be an encrypted volume with your files: check first.
What happens if you delete it?
Not recreated. Public installers can be downloaded again; your own disk images cannot.
How to remove it properly
Review each one: double-click a .dmg or .iso to see what is inside, then eject it. Find them with Finder search (Command-F) and a File Size criterion, or in System Settings › General › Storage › Documents (Large Files). Move the ones you no longer need to the Trash.
Quit the app that uses it, then move it to the Trash. Empty the Trash when you’re sure.
Before you delete it
Do not delete an encrypted disk image that asks for a password when opened, or an .img used by a virtual machine, unless you are sure it is no longer needed.
How MoreRoom helps
MoreRoom recognises this item and labels it “Review first”: it shows what’s inside, its size and last use, so you can decide. Nothing is removed without your say, and everything goes to the Trash first, with Undo.
Frequently asked questions
Is it safe to delete large .dmg, .iso and .pkg files on Mac?
Usually, after a check. Might hold something you care about. Look inside before removing it. Not recreated. Public installers can be downloaded again; your own disk images cannot.
Will Large disk images and installers come back after I delete it?
No. Not recreated. Public installers can be downloaded again; your own disk images cannot.
How do I remove Large disk images and installers properly?
Review each one: double-click a .dmg or .iso to see what is inside, then eject it. Find them with Finder search (Command-F) and a File Size criterion, or in System Settings › General › Storage › Documents (Large Files). Move the ones you no longer need to the Trash.