What Are Message Segments?
When sending SMS notifications through Waitwhile, messages are divided into segments based on their length and content. A message segment is a portion of a text message that fits within a specific character limit. The number of segments a message contains directly affects messaging costs and delivery.
Character Limits for Message Segments
The length of a single SMS message segment depends on whether the message contains standard characters (GSM-7) or special characters (Unicode):
Standard Characters (GSM-7 Encoding):
This is the standard encoding used for most text messages containing basic Latin characters, numbers, and symbols.
Single Segment: Up to 160 characters.
Multipart Messages: If the message exceeds 160 characters, it will be split into multiple segments. Each segment in a multipart message can contain 153 characters, as 7 characters are reserved for metadata to link the segments.
Special Characters (Unicode Encoding):
Used for messages containing special characters, emojis, or non-Latin scripts (e.g., Chinese, Arabic).
Single Segment: Up to 70 characters.
Multipart Messages: If the message exceeds 70 characters, it will be split into multiple segments. Each segment in a multipart message can contain 67 characters, as 3 characters are reserved for metadata.
Examples of Message Segments
Message Content | Character Count | Segments Used |
"Your appointment is confirmed." | 30 | 1 |
"Your appointment is confirmed. Please arrive 10 minutes early." | 72 | 1 |
"Your appointment is confirmed. Please arrive 10 minutes early. Reply STOP to unsubscribe." | 125 | 1 |
"Your appointment is confirmed 😊" (with emoji) | 32 (Unicode) | 1 |
"Your appointment is confirmed. Please arrive 10 minutes early. We look forward to seeing you! 😊" | 142 (Unicode) | 3 |
Why Message Segments Matter
Each segment counts as a separate SMS message when calculating costs. Understanding how segments work can help you:
Optimize messages to reduce SMS costs
Each message segment counts as a separate SMS for billing purposes. For example, a 320-character message using GSM-7 encoding would count as three segments (153 + 153 + 14 = 320).
Ensure messages are delivered properly.
Some mobile carriers may deliver segments out of order, leading to a fragmented or confusing experience for the recipient.
Longer messages take more time to send, increasing the chance of delays.
Avoid unnecessary splitting due to special characters or excessive length.
Can lead to increase costs and can impact message readability
Tips to Optimize Message Segments in Waitwhile
Keep Messages Concise:
Aim to keep messages under 160 characters (or 70 characters if using special characters) to avoid splitting into multiple segments.
Avoid Unnecessary Emojis and Special Characters:
Use plain text whenever possible to stay within GSM-7 encoding and maximize character limits.
Preview Your Message:
Waitwhile provides tools to preview messages and see how many segments they will use before sending.
Consider Alternative Communication Methods:
For longer messages, consider using email or other channels that don’t have character-based segmentation.
Note: Try it yourself! You can see how many segments your message is here using the Twilio segment calculator
Have additional questions or need assistance? Reach out to us via chat or at support@waitwhile.com