Whether you know it or not, you've probably been using SMS messages since you first got a cell phone.
What SMS means
SMS, or "Short Message Service," refers to standard text messages that are sent using a cellular signal instead of an internet connection, unlike iMessage or other web-based messaging services.
SMS messages are limited to 160 characters, which is why longer SMS messages are typically broken into parts.
SMS vs. MMS
MMS, which stands for Multimedia Messaging Service, is an extension of SMS. When you get an MMS message, SMS is the core technology behind that message.
Like SMS, MMS texts are also sent over a cellular signal. But, unlike SMS, they can include multimedia content like pictures, videos, and audio. MMS messages also don't have a formal character limit so you can send longer texts without worrying that your message will be broken up into parts.
While both SMS and MMS use your cellular network to send and receive messages between any type of phone, iMessage can use either Wi-Fi or your cellular network to send and receive messages only between Apple devices.
When SMS messages are used
The use of SMS messages depends on your phone carrier. For example, on an iPhone, you'll see the difference in the color coding of messages. Green bubble texts are SMS messages (used when the recipient doesn't have an iPhone), while gray or blue bubble texts are sent via iMessage.
For Android users, on the other hand, SMS messages are the default, unless you don't have access to a cell signal. But if you're using group-chatting apps, like WhatsApp or Telegram, you're never going to be using SMS messages since those services are internet-based.
Are SMS messages free?
Whether you can send SMS messages for free depends on your cell carrier and phone plan. Although it used to be common for US carriers to charge by the number for SMS messages both sent and received, it's now more common to have an unlimited plan where all texts are included in your rate. Even so, there's still typically a charge for SMS messages if you go outside of your coverage area or country.
Here are a few SMS rates for the larger companies:
- T-Mobile: All plans include unlimited texting within covered areas. Outside of those areas, the charge is $0.50 per text.
- AT&T: Without unlimited texting, you're charged $0.10 for each message — whether it's SMS or MMS — over your monthly limit. For pay-per-use texting, you're charged $0.20 per SMS message and $0.30 per MMS message.
- Verizon: If you don't have the unlimited plan, it's $0.20 per message sent and received in the Nationwide Rate and Coverage Area. International text messages cost $0.25 per message sent and $0.20 per message received.
