Check marks will appear next to each message you send. Here is what each one indicates:
- message successfully sent.
- message successfully delivered to the recipient's phone.
- the recipient has read your message.
In a group chat, the second check marks will appear when all participants in the group have received your message. The two blue check marks will appear when all participants in the group have read your message.
The Message Info screen shows you who has seen your message and when. Learn more about the Message Info screen on: Android | iPhone | Windows Phone | Nokia S40 | BlackBerry | BlackBerry 10
If you only see a single check mark next to your message, there is likely nothing wrong with WhatsApp or your phone. There may be several reasons why your message has been sent, but not delivered to your chat partner:
- Their phone might be off.
- They might be experiencing network connection issues.
- They might have seen the notification on their screen, but did not launch the app (especially common if the recipient uses an iPhone).
- They might have blocked you. For more information read this article.