Viscosity allows a number of credential types to be saved for VPN connections, such as username and passwords, private key passwords, proxy username and passwords, and certain other credentials. On macOS these credentials are stored in the Keychain, while on Windows they are stored in an encrypted database (tied to the computer and user account).

In most instances you will never need to manage these credentials yourself. Viscosity will automatically save them (if the “Remember details” checkbox is ticked) and retrieve them when the VPN connection requires them. If a VPN connection is deleted, Viscosity will delete the saved credentials as well (ignoring certain edge cases, such as system-wide proxy credentials in the Keychain).

A common mistake when your username/password changes for a VPN connection is thinking that the old credentials need to be manually deleted before entering new ones. Instead, when the old details are rejected by the VPN server Viscosity will automatically re-prompt you for the updated details. Simply enter the updated details, and they'll overwrite the old saved credentials.

In rare instances where you may manually want to delete saved credentials (for example, you wish to connect using a different username/password and the old credentials are still valid), there are a number of options available:

• You can duplicate the VPN connection in Viscosity, and then use the new VPN connection (and optionally delete the original one). To duplicate a VPN connection, open Viscosity's Preferences window, select your connection, click the button next to the Edit button, and select "Duplicate Connection".

• On macOS, the Keychain Access application can be used to view, modify, and delete saved credentials. To find a saved credential for your connection, open Keychain Access (located at /Applications/Utilities/Keychain Access), ensure that the "All Items" tab is selected, and enter "Viscosity" into the Search field.

• On Windows, the "Clear All Saved Credentials" option can be used to delete the saved credentials for all VPN connections. To user this, open Viscosity's Preferences window, select the Advanced tab, and click the Clear All Saved Credentials button.