Glossary

What is Blue bubble?

A blue bubble is the visual indicator that a message was sent as an iMessage between Apple devices, rather than as a green-bubble SMS through a carrier.

The color is a delivery signal people read instantly. Blue means the message travelled over Apple's messaging service with read receipts, typing indicators, high-quality media, and reactions available. Green means it fell back to carrier SMS or MMS.

For outbound sales, the distinction matters because recipients have learned to associate green-bubble messages from unknown numbers with automated marketing, while blue bubbles read as ordinary conversation.