Mountain Duck 17+

Mount remote storage as a disk

David Kocher

    • 3.7 • 33 Ratings
    • $39.99



Mountain Duck lets you mount server and cloud storage as a disk on your desktop. With Smart Synchronization, files are synchronized to the local disk when opened to allow offline usage and changes are uploaded in the background as soon as a connection is available. Open remote files with any application and work like on a local volume. Transfer files using Finder to remote servers, fast. Select files and folders to always keep offline on your computer. Other files are downloaded and cached on demand only and otherwise do not take space on your local disk. Encryption for data at rest using Cryptomator interoperable vaults prevent unauthorized access regardless of the server or cloud storage infrastructure.

Based on the solid open source foundation of Cyberduck, all major protocols are supported to connect to just about any server you want. Including FTP, SFTP, WebDAV, Azure Cloud Storage, Amazon S3, Google Cloud Storage, Google Drive, Dropbox, Backblaze B2 & OpenStack Swift.

What’s New

Version 4.15.3

• Cannot allocate memory failure mounting volume (macOS/Intel)

Ratings and Reviews

3.7 out of 5
33 Ratings

33 Ratings

Federmanhoyos ,

Really God But Support ?

I bought the application because its option of offline mode. And so far the application has been working pretty well. The complaint is that I cant open PDF files ( Preview or any other editor ) and write notes in the pdf. Every time I do that I receive a messages telling me that is not allowed and basically force me to save the document with a different name.

I have emailed to the product support, but guess what? No answer at all. Nothing.

Fixing the PDF editing error and fixing his support service I will 5 starts to the product

Developer Response ,

Files opened in and edited cannot be saved at the original location but the message "The original document can't be changed, so a duplicate with your changes has been created" is displayed in the title bar. As a workaround you can set a custom mount point in Preferences → Connection → Mount Location for volumes such as a ~/Volumes/ folder in your home directory. Also refre to our FAQ or known issues at

MichaelThwaite ,

One of the best

Extends my desktop to servers, sharepoint, S3 and more, reliably. But don't expect the attached disk to work exactly like your internal disk - it's a long way away! When you take that into consideration then this is one of the best tools out there.

Making an S3 bucket or a SharePoint or Google drive look like a local disk is no easy task. Things you do on a local disk like renaming files, moving a hundred files to a new folder, etc. become far more difficult when the wire between you and the disk is 2,000 miles long!

Take S3 for example, you can't rename or edit files in an S3 bucket yet Mountain Duck makes it seem as though you can - silently re-copying and renaming S3 objects in the background - more like a swan than a duck.

Shango80 ,

Fantastic - S3 As a Filesystem More

I love this application. I was previously on the G Suite plan with unlimited storage, but when that was phased out I needed a solution to let me have multi-system sync and offline access to large collections of data. Mountain Duck lets me do this; and with a combination of being able to use native AWS S3 and local S3 I can mix and match my storage tiers and pricing!

One request here -- would be great if we could enter our own preferences on the sizes of the local cache. The existing choices jump from 10 GB (not enough for some workflows) to 500 GB (more local disk than I have). Can we just enter a number in GB?

App Privacy

The developer, David Kocher, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.