If you’ve ever noticed that some of your text messages appear in blue bubbles and others in green, you’re not imagining things, they’re actually two different systems. Here’s what that means and how messaging on iPhone works.

Blue bubbles vs green bubbles

The Messages app on iPhone handles two types of message:

Blue bubble, iMessage. This is Apple’s own messaging service. It works when both you and the person you’re messaging have an iPhone (or another Apple device like an iPad or Mac). iMessages are sent over the internet, Wi-Fi or mobile data, rather than via your phone network.

Green bubble, SMS or MMS. This is a standard text message, sent via your mobile network. It’s what gets used when the person you’re texting has an Android phone, or when you don’t have an internet connection.

Your iPhone switches between the two automatically. You don’t need to do anything differently.

What iMessage can do that SMS can’t

iMessage has a few extra features that standard texts don’t:

Read receipts, you can see when someone has read your message (“Read” appears under it, if they have read receipts turned on)
Typing indicator, three dots appear when someone is writing back to you
Reactions, press and hold a message to add an emoji reaction (a thumbs up, heart, etc.)
Full-quality photos and videos, SMS compresses images significantly; iMessage sends them at full quality
Works over Wi-Fi with no signal, useful abroad or in areas with poor reception
Edit a message, press and hold a sent message and tap Edit (within 15 minutes of sending)

What about when there’s no internet?

If you have no Wi-Fi and no mobile data, iMessages can’t send. Your phone will either wait and retry, or, if you have mobile signal, send as a standard SMS instead (shown in green). You can turn this fallback on or off in Settings → Messages → Send as SMS.

Sending a message

Open the Messages app. Tap the pencil/compose icon in the top corner. Type a name or number in the To field. Type your message and tap Send.

If the send button is blue, it’ll go as iMessage. If it’s green, it’ll go as SMS.

Tips for messaging on iPhone

Mute a noisy group chat: In your message list, swipe left on the conversation and tap the bell icon (Hide Alerts). You’ll still receive the messages, your phone just won’t ping for each one.

Send a voice note: In iMessage, tap the microphone icon next to the text field, hold to record, then release. Note that iMessage voice messages expire after 2 minutes unless you tap “Keep”, so if it’s important, save it.

Delete a message you’ve sent: Press and hold a sent message → Undo Send (works within 2 minutes of sending).

Block someone: Open the conversation → tap the contact name at the top → scroll down → Block this Caller.

Not sure how something works on your iPhone, or want to get more comfortable with messages and apps? Get in touch with Hebden Tech Tutors, we’re here to help.