When sending SMS campaigns in Engage, it’s essential to understand how the cost per message is calculated to optimize your budget and the user experience. The price of an SMS depends not only on the number of messages sent but also on the length and content of the message. Here's how it works:
Characters per Message
A standard SMS can contain up to 160 plain characters. These characters belong to the GSM-7 encoding, which includes common letters and symbols. However, if your message contains emojis, Chinese characters, or other non-GSM-7 characters, the limit is reduced to 70 characters per message.
Example:
- If you send an SMS with 160 characters or fewer, you will be charged for a single message.
- If your message contains emojis or Chinese characters, you are limited to 70 characters before additional costs are incurred.
Message Segmentation
If the message content exceeds the character limits (160 for plain messages or 70 for messages with emojis or special characters), the SMS is split into smaller segments for delivery. Plain messages over 160 characters are split into 153-character segments to ensure proper reassembly when received.
Example:
- A message with 161 characters will be split into two segments: one with 153 characters and one with 8 characters. In this case, you would pay for two messages.
- A message with 350 characters will be split into three segments: two segments of 153 characters each and one smaller segment of 44, resulting in the cost of three SMS.
Use of Emojis or Chinese Characters
If your message includes emojis, Chinese characters, or other characters not supported by GSM-7, the message will use UCS-2 encoding. This reduces the character limit to 70 per segment. Like plain messages, if you exceed 70 characters, the message will be split into 67-character segments to maintain proper reassembly.
Example:
- A message with 71 characters and emojis will be split into two segments: one with 67 characters and another with 4 characters, resulting in the cost of two messages.
 It's important to note that while each segment is billed as an additional SMS, the message will appear as a single conversation bubble. |
Note: Although Engage allows you to create messages up to 1600 characters long, we recommend keeping your SMS within 320 characters. Staying within this limit not only optimizes costs but also ensures better deliverability and a smoother user experience.