How can you know if someone is online on WhatsApp?

Knowing if someone is currently online on WhatsApp depends on several factors, and the app itself doesn't provide a direct way to see real-time online status of contacts unless they've chosen to share it. However, there are a few indicators that can give you a sense of their activity:

1. **Online Status**:
   - When someone is actively using WhatsApp, you may see a green dot next to their profile picture in the chat window or within the chat list. This indicates they are currently online.

2. **Last Seen**:
   - WhatsApp shows the last time a user was active with a timestamp like "last seen today at [time]" or "last seen yesterday at [time]". This can give you a general idea of when they were last online.

3. **Typing Indicator**:
   - When someone is actively typing a message to you or in a group chat, you'll see a typing indicator (typically three dots) next to their name in the chat.

### Privacy Settings:

- **Privacy Settings**: WhatsApp allows users to control who can see their online status, last seen timestamp, and profile picture. Users can set these privacy settings to "Everyone", "My Contacts", or "Nobody".

### How to Check Online Status (Observational):

- **Observation**: If you notice the green dot or see someone typing, they are likely active on WhatsApp at that moment. However, these indicators are only visible when you are actively chatting with the person or looking at the chat list.

### Considerations:

- **Respect Privacy**: WhatsApp values user privacy, so respect the settings and preferences of others regarding their online status.

- **Offline Activity**: Just because someone isn't showing as online doesn't mean they are not using WhatsApp. They may have turned off their online status or have set privacy options to limit visibility.

WhatsApp provides basic indications of online status and activity, but the app prioritizes user privacy, so real-time monitoring of someone's online status is generally not possible unless explicitly shared or observed through active conversation.