Mac App Store

Mac App Store is the simplest way to find and download apps for your Mac.

To download Underpass from the Mac App Store, you need a Mac with OS X 10.6.6 or later. Learn More.


By Jeff Johnson

Open the Mac App Store to buy and download apps.


End-to-end encrypted chat and file transfer for complete privacy and security.

Underpass is different from every other encrypted chat app because it does not use a third-party service. It's just two devices and a password. Peer-to-peer. There's no signup. No account. No phone number, email, contacts, or any personal information requested, not even your real name.

You can chat securely over the internet or on a LAN, such as in an office, school, coffee shop, or home. All of your data is encrypted before it's sent over the network, and it can't be decrypted except by the other device using Underpass. Industry-standard AES-128 encryption algorithm.

Chat Features:
* File transfers of any file type
* Inline images, including animated gifs
* Unicode text and emoji

Underpass for iOS is also available, sold separately in the iOS App Store. You can chat with a Mac, iPhone, iPad, or iPod touch using Underpass.

What's New in Version 1.0.3

* The link to the App Store from the Help no longer automatically opens the App Store, because iTunes 12.7 does not have the App Store, and this causes an infinite loop between iTunes and your web browser.
* A few other minor improvements.


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View in Mac App Store
  • $4.99
  • Category: Utilities
  • Updated:
  • Version: 1.0.3
  • Size: 2.6 MB
  • Language: English
  • Seller:

Compatibility: OS X 10.11 or later, 64-bit processor

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