Practical Guide to Selecting Between GSM-7 and UCS-2 Character Encodings

The Importance of Encoding Selection

Encoding errors can result in garbled text and cause messages to be automatically split into multiple segments, thereby increasing billing costs. In severe cases, messages may be blocked or discarded by the carrier.

Practical Implementation

1. Overview of the Two Encoding Types

• GSM-7 Encoding: Suitable for English and basic symbols; supports up to 160 characters per message but does not support complex scripts such as Chinese or Arabic.


• UCS-2 Encoding: Supports a wide range of global characters, including those for minority languages; limited to 70 characters per message.




2. Implementation in Business Applications



• Automatically detect text content on the application side and switch to the appropriate encoding format.


• Do not mix encoding formats within a single message to prevent parsing errors.


• Create multilingual test cases to verify how the text is displayed.

For global businesses operating in multiple languages, use UCS-2 encoding by default for content in minority languages. Proper encoding selection prevents garbled text issues, optimizes message segmentation, and reduces unnecessary billing costs.