What is a Message Segment?

A message segment is the unit used to measure the size of your text message. While SMS may seem like a simple message of characters, it's actually sent in segments behind the scenes.

  • One segment = 160 characters (using standard characters like letters, numbers, and punctuation).

  • If your message goes beyond 160 characters, it’s broken up into multiple segments.

  • These segments are reassembled on the recipient’s phone to appear as a single, seamless message.

However, if your message includes special characters like emojis (😊🔥❤️), non-Latin letters, or symbols (like “—” or “®”), it uses Unicode encoding, which reduces the segment size to 70 characters per segment.

Using just one emoji or symbol means your entire message will be sent using Unicode encoding and the lower segment size. So messages with emojis or symbols need to be shorter than plain text messages to be below the maximum message size.

This example below shows how the exact same message doubles in segment size by using one or more emojis in the message, thus needing Unicode encoding to send the message.

 

What is the Maximum Message Segment you can send?

There’s technically no hard limit on the total number of segments, but most carriers support up to 10 segments in one message (which is about 1,600 characters ). After that, message delivery is not guaranteed and may be blocked or truncated.

*Note: We do see AT&T enforce the 10 segment limit more than other carriers.

Here’s a quick breakdown:

Character Type Characters per Segment Max Characters (~10 segments)
Standard (GSM-7) 160 ~1,600
Unicode (e.g., emojis) 70 ~700

Note: If a message is longer than one segment, each segment after the first uses a few characters for “metadata”, which helps stitch the message back together. This means:

  • A long standard message (GSM-7) uses 153 characters per segment after the first.

  • A long Unicode message uses 67 characters per segment after the first.

 

Things to Keep in Mind

  1. Longer Messages = More Segments
    Each segment counts as a separate message when sending messages. If you send a 320-character standard message, that’s 3 segments, not one.
     

  2. Emojis and Special Characters Shrink Limits
    Using a single emoji can reduce your segment size from 160 to 70 characters. That cuts your maximum message size in half. If you want to maximize message length, stick to plain text.
     

  3. Use Tools to Track Segment Count
    Our platform includes a character counter so you can calculate how many segments your message will use before sending (based on encoding type).

  4. Keep Messages Clear and Concise
    Shorter messages not only save money but are more likely to be read and acted on by customers.
     

  5. Test Long Messages When Possible
    If you need to send something long, do a test first to ensure it delivers as expected—especially if it includes links, emojis, or special formatting.