What is a segment?

Text messages are measured in units called message segments. A segment is essentially “the amount of data contained in the message.” For SMS messages, Scale to Win charges per message segment sent instead of per text.

Note: MMS messages - messages containing a picture, gif, or short video - do not consist of segments. Only SMS messages - messages of just text characters - are measured in segments.

The size of a segment depends on the number of characters in your message. Examples of characters include letters like “a” or punctuation like “!”.  A segment starts at 160 characters when using standard keyboard characters (A-Z, numbers, a few special characters). 

When your message is longer than 160 characters, it’s split into 153 character segments that are sent individually and then reassembled on the recipient’s phone. So a message of 161 characters would be sent as two segments: a 153 character segment plus another segment with the remaining 8 characters. 

However, when your message includes special characters like emojis, certain accented letters, or curly quotes, the segment is encoded differently and can hold only around 70 characters - see more on this below. 

Note: Account Owners can also view the total number of segments sent on your account on the "Usage" page.

To make this concept as easy to work within as possible, our platform does the counting work for you by calculating how many segments your message contains and how many characters you have left until you reach another segment. You can access this counter for each script you enter in the Script or Canned Responses tabs of a campaign by clicking on the script.

 Image displaying the segment counter for a script. The counter displays the total number of characters in the message, estimates the number of segments it contains, and tells you how many characters you can still add before adding another segment.

In the sample image above, the counter estimates the message will use 2 segments because it is 206 characters long. The counter also estimates that there are 100 characters left until the message reaches 3 segments in length. This is an estimate because of the use of custom fields - the green bracketed text in the example - which will populate a different result for each contact. Given that the custom fields in the image above (e.g.“texterAliasOrFirstName”) themselves are probably longer than most of the information that would replace them (e.g. “John” or “Elizabeth”) , it’s safe to assume that this message is going to stay at 2 segments. 

Taking a look at the number of segments in the initial message and responses is helpful to be able to accurately estimate how much you’ll be spending for the text campaign you’re about to launch. We strongly recommend keeping your messages under 4 segments if possible.

Standard versus unicode characters

 An important reason to pay close attention to the character counter and text segments is that you could unintentionally write a message that contains more segments than you mean to send. This is exactly why we included the segment estimator/character counter.

How could that be? As mentioned above, a single segment is 160 characters long when using standard characters, and 153 characters long once more than 160 characters are in the message. But if the message contains unicode characters, such as emojis or accents or non-English language characters, it causes the first segment to contain just 70 characters. Once you pass the 70 character limit, the segment size shrinks down to 63 characters. So a message with an emoji and 71 characters would be sent as two segments of 63 and 8 characters, respectively.

Here’s a table showing what counts as a standard versus a unicode character:

Let’s look at an example of how unicode characters change segment lengths. In the image below, we have the same message from before, but a thumbs-up emoji has been added:

Image displaying the effects of adding an emoji to a message - the estimated number of segments has doubled.

Now the message is 4 segments long, whereas before it was safely at 2 segments.

Why? Because the message has to be sent in a different way in order for that emoji to show up on the recipient’s phone. Essentially each segment now contains half the amount of characters. And that applies to the entire message, not just the segment where the emoji is.

You can still send any character you can possibly enter into the script box, just be aware it will result in a shorter number of characters per segment.

For example, this message would be 1 segment with or without the emoji, but the emoji dramatically shortens the characters per segment. 

 Image displaying the effects of adding an emoji - even though the message still is only one segment long, the number of characters you could still add while remaining in the segment has significantly decreased.