Privacy
The current implementation has no application telemetry.
App data
Section titled “App data”ADNS stores the provider selection, selected NextDNS profile, device hostname, Wi-Fi names and rules, notification choices, and activation state locally so the features you configure can work. With Android backups disabled for the app, its data is not backed up.
If you connect a NextDNS account, the password and any two-factor code are used transiently for sign-in and are not stored. The signed-in email (or account label for API-key sign-in) and API key are encrypted and persisted locally until you log out. Signing out removes that local account session.
The API key is used for the NextDNS account requests you make. The Normal build checks GitHub Releases at launch and only notifies about an available update; the FOSS build has no update check.
Website
Section titled “Website”The site itself adds no visitor tracking.
See Permissions and account access for when optional Android access is requested, what it can expose, and how to revoke it.