Open the Messages app
Tap and hold the text message or conversation
Select Delete or the trash icon
Confirm the deletion
To erase multiple messages, open the conversation
Tap and hold a message
Select more messages if needed
Tap Delete
Confirm the deletion
To delete an entire thread, go to the conversation list
Tap and hold the thread
Select Delete
Confirm the deletion
To delete all messages in an app, open the app settings if available
Clear the app data only if you want to remove all stored messages from that app
Check archived conversations if the thread is not visible
Delete messages from synced devices if your messages are backed up or synced
Empty the trash or recently deleted folder if your messaging app has one