To delete old DMG files on Mac, open Finder, select your Downloads folder, search for .dmg with the scope set to Downloads, select all results, and move them to Trash. A .dmg is just the installer disk image for a Mac app; once the app is in your Applications folder, the installer is dead weight.

TL;DR

  • A .dmg (Apple Disk Image) is a one-time installer; deleting it does not affect the installed app.
  • Bulk-delete them in Finder by searching .dmg scoped to Downloads, then empty Trash.
  • Repeat the same sweep for .pkg installer packages.
  • Keep a .dmg only if the app is paid and no longer downloadable, or licensed to that exact installer.
  • Years of installers can hold 20-50 GB; clearing them is one of the fastest safe wins on a full Mac.

What is a DMG file on Mac?

A DMG (Apple Disk Image) is a virtual disk that behaves like a CD. When you download an app from outside the Mac App Store, you double-click the .dmg, it mounts as a drive, you drag the app into Applications, and you eject it. The app now lives independently in Applications, but the original .dmg stays in your Downloads folder doing nothing. A single installer for a heavy app like Photoshop or Office can run 1-5 GB, so a couple of years of downloads quietly stack up.

How do I bulk-delete DMG files in Finder?

Finder's scoped search is the fastest way to round them all up at once:

  1. Open Finder.
  2. Click Downloads in the sidebar.
  3. Type .dmg into the search bar (top right).
  4. Under the search bar, switch the scope from This Mac to Downloads so you only touch installers, not system files.
  5. Press Command + A to select everything.
  6. Right-click and choose Move to Trash, then empty the Trash.

Then repeat the exact same sweep with .pkg to catch older installer packages, which work the same way but install through a guided wizard.

DMG vs PKG vs the installed app: what's safe to delete?

Item What it is Safe to delete?
.dmg in Downloads Installer disk image Yes, once the app is in Applications
.pkg in Downloads Installer package Yes, after install completes
App in /Applications The actual program No, this is what you use
Mounted disk on Desktop An open .dmg Eject first, then delete the file

The key point: the installer and the app are two separate things. Removing the installer never removes the program.

Is it safe to delete DMG files?

Yes. Deleting a .dmg or .pkg does not touch the installed application, your documents, or any settings. The only thing you lose is the ability to reinstall from that local copy, and for the vast majority of apps you can simply re-download a fresh installer if you ever need it. Until you empty the Trash the files are also recoverable, so there's a built-in safety net.

Keep a .dmg only in two cases: the app is paid and its license was tied to that specific installer, or the app is no longer available to download anywhere. In every other situation the installer is pure overhead.

What else fills a Mac after installers are gone?

If your drive is still heavy after clearing installers, the next culprits are usually large media, duplicate files, and opaque system storage. A good next step is understanding the mysterious System Data category on Mac and how to safely clean the disk, which is often the single largest chunk on a full machine. If duplicate documents and downloads are part of the bloat, see how much space duplicate photos can actually save for why the category is worth chasing, and verify byte-for-byte matches with a free local file hash checker that runs entirely in your browser. When deciding which copies to keep, duplicate vs similar photos: what should you delete is a useful rule of thumb. For the bigger picture on what's eating your space, the content and data utilities hub collects local-first tools for tidying files.

FAQ

Does deleting a DMG file delete the app?

No. A .dmg is only the installer disk image. Once you've dragged the app into your Applications folder, the app runs independently, and deleting the original .dmg has no effect on it.

How much space can old DMG files free up?

Installer images often range from a few hundred MB to 5 GB each. After a year or two of downloads, a typical Downloads folder can hold 20-50 GB of unused .dmg and .pkg files.

Can I recover a DMG after deleting it?

Until you empty the Trash, yes, the file is still there. After emptying, you can almost always just re-download a fresh installer from the developer's website, so deleting is low-risk.

What's the difference between a DMG and a PKG file?

Both are installers. A .dmg mounts as a virtual disk you drag an app from, while a .pkg runs a guided installer wizard. Both are safe to delete once installation is complete.

Clean up the rest of your storage

Clearing installers is a quick desktop win, but most people's real storage problem is on their phone. If your camera roll and app caches are out of control, Cleanor for iPhone finds duplicates, large videos, and screenshot clutter locally, with nothing uploaded to the cloud.