SMS Segment Optimization with Smart Encoding
SMS segment optimization helps reduce unnecessary message segments and control SMS costs. DialNext automatically applies Smart Encoding to outgoing SMS messages, replacing supported Unicode characters with GSM-7-compatible alternatives where possible.
This helps messages stay within GSM-7 encoding when possible and reduces unnecessary segmentation.
What Is an SMS Segment?
An SMS segment is an individual unit used to transmit a text message. The number of segments depends on both the length of the message and the character encoding used.
A standard GSM-7 SMS supports up to 160 characters in a single segment, while a message that requires Unicode/UCS-2 encoding typically supports up to 70 characters.
For longer, concatenated messages, the limits are generally:
| Encoding | Single Segment | Multi-Segment |
| GSM-7 | 160 characters | 153 characters per segment |
| Unicode/UCS-2 | 70 characters | 67 characters per segment |
Longer messages are split into multiple segments and typically reassembled on the recipient’s device.
How SMS Segment Optimization Works
SMS messages can use different character encodings.
Most standard Latin letters, numbers, and common symbols can be encoded using GSM-7. However, some characters—such as smart quotation marks, certain special symbols, emojis, and characters from many non-Latin scripts—may require Unicode encoding.
A single unsupported character can cause the message to use Unicode/UCS-2 encoding, reducing the number of characters available per segment and potentially increasing the total number of SMS segments.
DialNext Smart Encoding helps prevent unnecessary Unicode encoding by automatically replacing supported Unicode characters with visually similar GSM-7-compatible alternatives before the message is sent.
Smart Encoding Examples :
| Original | GSM-7-Compatible Replacement |
| “ ” | ” “ |
| ‘ ’ | ‘ ‘ |
| … | … |
For example:
Hello “John”
can be automatically converted to:
Hello “John”
before the message is sent.
Smart Encoding only replaces characters when a suitable GSM-compatible alternative is available. Characters such as emojis or characters from many non-Latin scripts may still require Unicode encoding.
Why SMS Segment Count Matters
SMS usage and costs often depend on how many segments a message requires. Even a relatively short message may use additional segments when its encoding changes from GSM-7 to Unicode.
For example, a Unicode smart quote can trigger Unicode encoding. However, Smart Encoding can replace supported Unicode characters with GSM-compatible alternatives. As a result, replacing a smart quote with a straight quote can help keep the message in GSM-7 when all other characters are compatible.
Benefits of SMS Segment Optimization
- Reduce unnecessary SMS segments by keeping compatible messages in GSM-7 encoding where possible.
- Control messaging costs by avoiding additional segments caused by replaceable Unicode characters.
- Improve SMS compatibility across carriers and devices.
- Automatic optimization with no manual character cleanup required for supported replacements.
Is Smart Encoding Enabled by Default?
Yes. DialNext automatically applies Smart Encoding to SMS messages sent from the DialNext Inbox.
No additional configuration is required.
SMS Segment Optimization FAQs
Will Smart Encoding change the meaning of my message?
Smart Encoding replaces supported special characters with visually similar GSM-7-compatible alternatives while preserving the intended message wherever possible.
Why does SMS segment count matter?
SMS messages can be billed based on the number of segments used. Longer messages or messages requiring Unicode encoding may use more segments and therefore cost more to send.
Does an emoji affect SMS segmentation?
Yes. Emojis generally require Unicode encoding. This can reduce the single-segment character limit from 160 GSM-7 characters to 70 Unicode characters and may increase the number of segments required.
Can Smart Encoding convert every Unicode character?
No. Smart Encoding only replaces supported characters when an appropriate GSM-7-compatible alternative exists. Emojis and many non-Latin characters may continue to use Unicode encoding.
Can I disable Smart Encoding?
Smart Encoding is automatically applied by DialNext to help optimize SMS segment usage and messaging costs.
Need Help?
For SMS delivery, segmentation, or encoding questions, contact help@dialnext.io
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