Open the Messages app
Open the conversation
Look for the word Read under the latest message you sent
Check for a read receipt time under your message
If you only see Delivered, the message was sent but not confirmed as read
If you see no Read or Delivered status, read receipts may be off or unavailable
Make sure both you and the other person use iMessage
Read receipts must be enabled for the other person to see when they read your text
If the chat bubble is green, read receipts do not apply
If the chat bubble is blue, read receipts may appear if enabled
Check Settings
Tap Messages
Turn on Send Read Receipts to let others know when you read their texts