There are three ways to find out if a user is online:

1. Using a chat module to check if a dialog participant is online. Check our guides here:

iOS SDK – Chat | Dialogs | iOS SDK | QuickBlox

Android SDK – Chat | Dialogs | Android SDK | QuickBlox

JavaScript SDK – Chat | Dialogs | JavaScript SDK | QuickBlox

React Native SDK – Chat | User Presence | QuickBlox

Flutter SDK – Chat | User Presence | QuickBlox

2. Using a chat contact list:

iOS SDK – Chat | User presence | iOS SDK | QuickBlox

Android SDK –  Chat | User presence | Android SDK | QuickBlox

JavaScript SDK – Chat | User presence | JavaScript SDK | QuickBlox

3. Ping user:

iOS SDK – Chat | User presence | iOS SDK | QuickBlox

Android SDK –  Chat | User presence | Android SDK | QuickBlox

JavaScript SDK – Chat | User presence | JavaScript SDK | QuickBlox

React Native SDK – Chat | User Presence | QuickBlox

Flutter SDK – Chat | User Presence | QuickBlox

Feel free to check our official documentation for more information that will help you to integrate QuickBlox services into your applications / projects or contact our Support team by submitting a ticket if you have any other questions.