How do you write "in WhatsApp" or "on WhatsApp" - briefly?
The correct preposition to use with the app name "WhatsApp" is "on". Therefore, you should say "on WhatsApp" rather than "in WhatsApp".
How do you write "in WhatsApp" or "on WhatsApp" - in detail?
The correct choice between "in WhatsApp" and "on WhatsApp" depends on the context in which these phrases are used. When referring to the act of sending a message, the appropriate phrase is "on WhatsApp." For example: "I sent him a message on WhatsApp." This usage implies that the action of messaging takes place within the platform, similar to how one would say "on Facebook" or "on Instagram."
On the other hand, when discussing content or information that exists within WhatsApp, such as a specific message or conversation thread, the preferred phrase is "in WhatsApp." For instance: "The information was stored in WhatsApp," indicates that the data resides within the application. This usage parallels how one might say "in an email" or "in a document."
By adhering to these distinctions, users can ensure their language is both accurate and clear, effectively communicating whether they are referring to actions taken on the platform or content that resides within it.