Help & Technical Support

How to install DirMerge on macOS

Option 1 (Recommended): Install directly from the Mac App Store for automatic background updates and seamless StoreKit licensing.

Option 2 (Standalone .dmg): Download the DirMerge.dmg installer, double-click to mount, and drag the DirMerge icon into your Applications folder.

Option 3 (Homebrew Cask): Install via Homebrew Cask with a single terminal command:
brew install --cask zhenqiang-sun/tap/dirmerge
Maintains automatic path symlinks and effortless CLI invocation.

How to open if macOS shows an unidentified developer warning

If your Mac displays a security notification upon first launch, simply right-click (or Control-click) the DirMerge.app icon in your Applications folder and select Open, then click Open in the confirmation dialog. Alternatively, navigate to System Settings > Privacy & Security and click Open Anyway.

Does DirMerge overwrite or delete files in my source folder?

Never. The Source directory is mounted and accessed strictly in read-only mode. DirMerge will never delete, move, or modify any file inside your reference folder.

How does APFS Zero-Space Cloning save disk space?

On Apple APFS drives, DirMerge creates Copy-on-Write references rather than copying raw bits. A 50 GB photo shoot or video archive clones in milliseconds while consuming 0 bytes of extra disk space.

What happens if a conflict occurs with an existing file?

Before replacing any conflicting file in your Target directory, DirMerge creates a safe rollback snapshot. If you made an error, click Undo (or press ⌘Z) to restore every replaced item.

Does DirMerge support external drives formatted with exFAT or FAT32?

Yes. While zero-space cloning requires APFS, DirMerge seamlessly supports exFAT, FAT32, and HFS+ volumes with high-speed buffered streaming and complete snapshot protection.

How do I restore my Pro purchase on a new Mac?

Open DirMerge, click the Unlock Pro button, and click Restore Purchase at the bottom of the paywall window. Since purchases are tied to your Apple ID via StoreKit, it will unlock instantly without charging you again.

How do I redeem an official Offer Code (e.g. DIRMERGEVIP2026)?

Open DirMerge, click Unlock Pro, and click Redeem Offer Code in the paywall window to redeem your code directly through the official Apple App Store system.

What keyboard shortcuts are available in DirMerge?

DirMerge is designed for high-efficiency macOS workflows:
• ⌘+ / ⌘-: Increase or decrease interface font size (100%, 115%, 130%)
• ⌘0: Reset font size to default
• ⌘[: Instantly swap Source and Target directory paths
• ⌘Z: Undo the most recent folder merge batch
• ⌘R: Refresh and re-scan folder differences