Mountain Duck 1.7

Mountain Duck 1.7 is now available with a focus on fixes for stability and performance improvements by an improved connection management. On Windows, the user interface is completely rewritten based on the Windows Presentation Foundation.

Mountain Duck 2.0 coming this spring will support transparent client-side encryption using Cryptomator interoperable vaults to secure your data on any server or cloud storage mounted.

Tabs Everywhere

If you have installed macOS Sierra, you can now use tabbed windows in Cyberduck 5.2 or later. You might want to enable tabs by default when choosing File → New Browser by selecting in System Preferences the checkbox Dock → Prefer tabs when opening documents: Always. New browser windows and the transfer window will then be displayed in a single window frame with a tab bar. You will also new menu items View → Show Tab Bar and Window → Merge all Windows.


Refer also to Use tabs with apps on your Mac.

S3 Transfer Acceleration

Amazon S3 Transfer Acceleration enables fast, easy, and secure transfers of files over long distances between your client and an S3 bucket. Transfer Acceleration takes advantage of Amazon CloudFront’s globally distributed edge locations. As the data arrives at an edge location, data is routed to Amazon S3 over an optimized network path. In general, the farther away you are from an Amazon S3 region, the higher the speed improvement (up to 300% faster) you can expect from using Amazon S3 Transfer Acceleration.

Cyberduck 5.2 and Mountain Duck 1.6 now uses the accelerate endpoints for file transfers to S3 when enabled for the bucket. Refer to the wiki for more information.



Mountain Duck gained the ability to mount remote volumes as read-only and forbids writes to the remote server on the operating system level. This will pose most useful to users mounting productive environments and will want to make sure nothing is written to the server but files are only readable.


Read Only Mount Option