Does it use your data when you iMessage or text someone?

Is data used on your iPhone when you iMessage or text someone? I'm not really sure, so just asking.

Text messages, no, they are counted differently.

iMessage, however, does use your data. But the size of text messages are pretty small so I wouldn't worry about running out of data, even if you use it a lot. When you are on Wi-Fi, it will send the messages through there and not use the data. Sending a lot of pictures or videos through iMessage will use more data, so maybe that is something to avoid unless on Wi-Fi.