SMS messages are encoded and split into segments. You are billed per segment.
Segment Calculator
Use this interactive tool to check how your message will be encoded and how many segments it will use:Encoding by Sender Type
| Sender Type | Default | Fallback |
|---|---|---|
| Long Code | GSM 7-bit | UTF-16 |
| Toll-Free | GSM 7-bit | UTF-16 |
| Short Code | ASCII 7-bit | UTF-16 |
| Alphanumeric | GSM 7-bit | UTF-16 |
If your message contains characters outside the default encoding’s character set, the fallback encoding will be used automatically.
The text content of MMS and RCS messages use UTF-8 encoding by default.
Character Limits
Messages are split into segments based on encoding. Each segment holds 140 bytes, with 6 bytes reserved for multi-part headers. You are billed per segment, up to a maximum of 10 segments.| Encoding | Single Segment | Multi-Part Segment |
|---|---|---|
| GSM 7-bit | 160 chars | 153 chars |
| ASCII 7-bit | 160 chars | 153 chars |
| ASCII 8-bit | 140 chars | 134 chars |
| UTF-16 | 70 chars | 67 chars |
UTF-16 characters use 2 bytes each (70 chars/segment). However, emojis use 4 bytes each and count as 2 characters, reducing capacity accordingly.