Check for a read receipt or “seen” status in the messaging app
Look for a timestamp showing when the message was opened
See whether the app shows delivered and read indicators separately
Check if typing indicators appear after sending the message
Review the app’s message info or details screen
Confirm whether read receipts are enabled on both devices
Note that some apps only show read status in chats, not SMS
Understand that read status may not appear if the other person disabled it
Understand that read status may not appear if the app or device is offline
Understand that read status may not appear if the message was sent as standard SMS
Check whether the app supports read receipts at all
Look for a blue checkmark, double checkmark, or similar read indicator if the app uses one