Because of the way text messages are formatted for sending, certain characters can cause issues that might make your texts larger in size (and more expensive to send) than you planned. We’ll explain the basics of how campaigns are structured and give you some tips to keep your text campaigns efficient and cost-effective.

Text Message Segments

Text messages are built in chunks called segments that are based on file size in bytes, not number of characters. Segments are how mobile carriers interpret and send your data. Although smartphones don’t have the same limitations that older, 160-character phones did, SMS messages are still structured the same way. The total cost of your campaign, and how quickly and efficiently your messages are sent, depends on the number of segments it uses. 

Emojis and some characters and symbols take up extra space in a segment. Certain special characters take up more space because they don’t appear in the standardized character library for most SMS providers. As a result, messages using these characters have to be encoded in a special way in order to display properly, and the behind-the-scenes code uses up valuable segment space.  For example, including an emoji in a message typically drops your segment character limit from 160 to 70.

Another factor that can impact your total segments for a message are the opt-out instructions that may be appended to the end of a message, '|To stop these messages reply STOP'. The opt out instructions will be included in the first message to any recipient as well as once every thirty days for each recipient.

This means that a message can appear to be well below a character limit but still take up multiple segments, and that two text messages that look almost identical can have very different sizes (and sending costs).

Troubleshooting

When you create a new text campaign, pay attention to the Segments box below the window. If you add a character with a large file size -- even if you can’t tell by looking at the text - you will see the number of segments increase. 

The above message uses a standard character - the apostrophe (‘) in We’re.

This message uses a non-standard apostrophe (`), which requires extra space to be displayed.

Emojis also take up extra space in segments, especially if you are using multiples.

Some special characters are easy to use by accident since they’re almost interchangeable with standard ones. For example, the ` on the left is a special character, but the ‘ on the right is not.

GSM-7 is the name of the currently widely accepted set of standard characters for SMS messages. Lists of GSM characters are available online for reference. Check the segment count on your draft messages to see if they match expectations. If the segment count is higher than you think it should be, you may have added special characters that are causing the message to take up more room than you expected.

Tips/Best Practices

• The character limit for text campaigns is 300. This doesn’t correlate with the number of segments your message will use, so pay attention to the segment count when you are drafting the campaign.
• Look out for special characters that may be inadvertently affecting your segment count, and replace them with standard characters.
• To make the best use of emojis, consider editing down in other places so you can add some visual excitement while keeping your segment and character count as low as possible.

Following these best practices will help you craft your messages with care and get information out to your customers without adding unnecessary costs to your campaigns.