Version 3.7 of DropDMG is now available.

DropDMG makes it easy to create a professional disk image for your app. Disk images pack entire folders or disks into a single compressed file, either for transport across the Internet or simply for backup or archival. They are Apple’s preferred format for distributing Mac software and the only archive format whose contents you can directly access in the Mac Finder—no extraction or third-party software required.

Deliver your Mac app on a .dmg file with a software license agreement, a custom volume icon, and a precise icon layout atop a Retina-optimized background picture. Customers can install simply by dragging and dropping the app onto the convenient Applications folder link. Code-sign your .dmg so that macOS knows it can be trusted after download.

This is a free update for owners of DropDMG 3.0 that includes the following enhancements:

• Updated DropDMG’s application icon for macOS Tahoe 26 and the new Liquid Glass design language. It no longer appears in “squircle jail” and now adapts as you change the macOS appearance to use the Dark, Clear, and Tinted icon styles.
• Added images for each menu item when running on macOS Tahoe 26.
• Added support for disk image files in the new Apple Sparse Image Format (ASIF):
  • Like the old .sparseimage format, the .asif format uses a single file and only consumes disk space based on the amount of data stored (rather than the disk image’s logical capacity). It is much faster than either the .sparseimage or .sparsebundle format but requires macOS Tahoe 26 or later.
  • Most of DropDMG’s feature set works with ASIF disk images. You can:
    • Create blank ASIF disk images, using the APFS file system, and specify the capacity and volume name.
    • Create new ASIF images from folders, packages, and individual files, with various options for specifying the destination, filename, and volume name.
    • Create new ASIF device images from attached disks.
    • Enable 256-bit AES encryption. When creating a batch of encrypted ASIF images, you only have to enter the passphrase once. Or you can have DropDMG read it from a pre-existing keychain entry.
    • Convert .dmg, .sparseimage, and .sparsebundle disk images to the ASIF format. When doing this, DropDMG can add a license agreement, code signing, or optimize the image for restores, if the destination format supports that. This works even if both the source and destination images are encrypted, whether or not the passphrases are the same.
    • Convert archives (.zip, .tar, .tar.bz2, etc.) to the ASIF format.
    • Convert ASIF disk images to other disk image (.dmg and .sparsebundle) or archive (.zip, .tar, .tar.bz2, etc.) formats.
    • Convert an ASIF disk image to a new ASIF disk image (e.g. to change the encryption).
    • Mount Image… with an ASIF disk image. You can control whether or not the disk image is mounted with ownership information, whether changes are saved to a shadow file, and whether the disk image is mounted on the desktop or at an arbitrary location in the filesystem. If you bulk mount multiple encrypted disk images, you only have to enter the passphrase once if it’s the same for all of them.
    • Change Image Passphrase… for an ASIF disk image.
    • Compact Image… with an ASIF disk image.
    • Get Image Info… for ASIF disk images.
    • Use the dropdmg command-line tool or AppleScript to control or automate DropDMG.
  • Some features do not work with ASIF disk images, due to macOS’s more limited support for them. You cannot:
    • Directly convert ASIF disk images to the .sparseimage, bzip2 .dmg, .cdr, or .iso formats or to a segmented .dmg format. However, this is possible by first converting to a different intermediate format.
    • Choose the less secure 128-AES encryption when creating an ASIF disk image or directly converting one to another format. If you really want to use it with an older format, you can do a two-step conversion.
    • See a determinate progress bar during operations on ASIF disk images.
• Additional updates for macOS Tahoe 26:
  • The Custom volume icon option’s badging has been updated for the new mounted disk image icon’s size and perspective.
  • For apps that have not updated their icon for Liquid Glass, the Custom volume icon option will now use the source app’s original icon to create the badge, rather than the “squircle jail” icon that macOS supplies.
  • Updated the window layouts, e.g for the new button sizes and window corner radius.
  • Updated the documentation and screenshots.
• DropDMG now tries to make sure the window’s path bar is hidden when setting the layout of a mounted disk image.
• Updated the Signing section of the manual.
• Updated the French, Italian, and Chinese localizations.

DropDMG 3.7 works with macOS 10.13 through macOS Tahoe 26. Older DropDMG versions are available for older versions of macOS. In-depth information about DropDMG is available in the manual.

If you enjoy using DropDMG, please take a moment to review it on the Mac App Store, MacUpdate, or Product Hunt or to mention it on Twitter, Mastodon, Instagram, Facebook, or your own site. We’d really appreciate it.

Update (2025-09-17): DropDMG 3.7 has been submitted to the Mac App Store and is awaiting approval from Apple.