How to Change From Text Message to iMessage on iPhone
If you've ever noticed some of your messages showing up in green bubbles and others in blue, you've already seen the difference between a standard SMS text message and an iMessage. Switching between the two isn't always a manual process — but understanding why it switches, and how to control it, makes a real difference in how you communicate.
What's the Difference Between SMS and iMessage?
SMS (Short Message Service) is the traditional text messaging standard. It works through your carrier's cellular network, costs carrier rates (unless you have unlimited texting), and can be sent to any phone regardless of brand or operating system.
iMessage is Apple's proprietary messaging platform. It runs over Wi-Fi or mobile data, is encrypted end-to-end, and only works between Apple devices — iPhones, iPads, Macs, and Apple Watches. When iMessage is available, Apple's Messages app uses it automatically. When it's not, the app falls back to SMS.
That's the core logic: iMessage is the default when possible; SMS is the fallback.
The color tells you which one is active:
- 🔵 Blue bubble = iMessage
- 🟢 Green bubble = SMS or MMS
Why Your Messages Might Be Sending as SMS Instead of iMessage
There are several reasons why a conversation might default to SMS even when you'd prefer iMessage:
- The recipient doesn't have an Apple device. iMessage requires both parties to be on Apple hardware. If you're texting an Android user, it will always send as SMS.
- iMessage is turned off on your device or theirs.
- Poor or no internet connection. iMessage needs Wi-Fi or cellular data to function. No connection means no iMessage.
- The recipient's iMessage isn't activated. New iPhones or recently reset devices may not have iMessage set up yet.
- Your Apple ID or phone number isn't verified within iMessage settings.
How to Turn iMessage On
If iMessage isn't active on your device, here's where to find the toggle:
- Open Settings
- Scroll down and tap Messages
- Find the iMessage toggle at the top
- Switch it on (it turns green)
Once enabled, your iPhone will attempt to use iMessage for any conversation where the other person also has it active. There's no need to manually select iMessage per conversation — the app handles it.
How to Force a Specific Message to Send as iMessage (or SMS)
The Messages app switches automatically, but you do have some manual control:
To send as SMS when iMessage is available:
- Press and hold a sent message
- Tap Send as Text Message (if the option appears)
This is useful if iMessage delivery seems to be stalling or failing.
To send via iMessage when a thread shows green: This usually isn't possible if the contact doesn't have an Apple device. However, if you believe they do and it's still showing green, try:
- Sending to their Apple ID email address instead of their phone number
- Asking them to check if iMessage is enabled on their end
iMessage Delivery and Send Failures
When iMessage fails to deliver, the app will typically offer to send as SMS instead. You'll see a red exclamation mark with an option labeled Send as Text Message. Tapping it switches that specific message to SMS.
You can also control this behavior globally:
- Go to Settings → Messages
- Toggle on Send as SMS
With this setting on, any iMessage that fails will automatically retry as an SMS — without you having to intervene each time.
Variables That Affect How This Works
Not every setup behaves identically. Here's what shapes your experience:
| Factor | Effect on iMessage vs SMS |
|---|---|
| Recipient's device | Android = always SMS; Apple = iMessage possible |
| Internet connection | No data = iMessage unavailable |
| iOS version | Older versions may have iMessage bugs or missing features |
| Carrier settings | Some carriers affect SMS fallback behavior |
| Apple ID sign-in status | Signed out = iMessage inactive |
| Dual-SIM or eSIM setup | May affect which number iMessage registers to |
Managing iMessage Across Multiple Devices
If you use iMessage on both an iPhone and a Mac (or iPad), messages sync across devices through your Apple ID. This means a conversation you start on your iPhone can continue on your Mac.
However, this also means that if iMessage is signed out on one device, that device may miss messages or show gaps in conversations. Keeping your Apple ID consistent across devices keeps iMessage working seamlessly.
When iMessage Behaves Differently for Groups
Group messages follow similar rules with one important nuance: if even one person in the group doesn't have an Apple device, the entire group chat may revert to MMS (Multimedia Messaging Service) rather than iMessage. This is why group chats sometimes show green even when most participants have iPhones.
Whether that matters to you — or whether you'd prefer to use a cross-platform messaging app for mixed groups — depends heavily on who you're communicating with and how often. ✉️