What's the Difference Between iMessage and SMS?

Wondering why you see green and blue messages on your iPhone? Here's what you need to know.

If you’re an iPhone user, you may have wondered why some messages appear in blue bubbles while some are in green—in some cases, you’d get a duplicate message with blue and green speech bubbles.

This isn’t just a cute gimmick—it’s Apple’s way of helping you tell apart an iMessage from a regular text message or SMS. But we’re just scratching the surface. Read on to learn how the two messaging services differ.

iMessage Exclusivity

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All mobile phones, including your iPhone, can send texts (also known as SMS or Short Message Service), using a cellular network—whether you’re on prepaid or subscribed to a plan.

On the other hand, iMessage is exclusively for Apple users. Even if iMessage is turned on, it will not work unless your recipient also uses an Apple device. Even if your recipient is indeed an Apple user but doesn’t have their iMessage feature turned on, it still won’t work.

Using Internet Versus Cellular Networks

You can send a text message to anybody with your iPhone as long as you have a SIM card that connects your phone to a carrier’s text messaging plan.

You can also send MMS to send multimedia content, like pictures, files, or links, to other people via a cellular network. However, they require more data than SMS, so your carrier will charge you more.

Related: iPhone Won’t Send Text Messages? Tips and Fixes

In contrast, iMessage is Apple’s built-in messaging service that uses your data connection or Wi-Fi to send all kinds of media—from images to videos to Memoji to voice recordings.

Sending an iMessage is free when you’re using the internet; however, sending an iMessage through data will cause a deduction from your data allowance.

iMessage Offers Unlimited Character Count

Text messaging allows you to send basic text messages, with character limits ranging from 70 to 160 characters, depending on your device and area.

However, most modern phones allow you to send longer messages and break them into chunks before sending them to the recipient. Then, their devices will join these multiple messages and present them as one long message.

The downside here is that carriers will charge the sender per 160-character chunk. On the other hand, there is no such limit on iMessage. Or if there was, the limit would be around 20,000 characters.

iMessage Has Better Security

Text messages are not encrypted. This means that your messages can be viewed by carriers or the government and intercepted by hackers. SMS can also leak metadata or general information about the text.

iMessage, on the other hand, is end-to-end encrypted. This process ensures that only the actual recipient can listen to or understand what was sent. Everything—from messages to voice messages and images—is encrypted when you’re using iMessage.

These Are Some Stark Differences

While it would initially seem that they only differ in appearance, the two messaging services have stark differences.

Standard text messaging is valuable in its own right. However, if you find yourself restricted because of its limited capabilities, know that your iPhone is equipped with a powerful messaging service for a more versatile way of communicating.

About The Author

Rachel Melegrito (66 Articles Published)

Rachel Melegrito left her career as a university instructor to become a full-fledged content writer. She loves anything Apple —from iPhones, to Apple Watches, to MacBooks. She is also a licensed occupational therapist and a budding SEO strategist.

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