What is the maximum character length of SMS messages?

It is possible to send SMS messages in a variety of text-based languages using the SMS API and Web Platform provided by SMS Connexion. The languages include English, French, Spanish, Chinese, Arabic, and more.

Messages with only GSM 7-bit characters can have no more than 1,530 characters. Messages with more than 160 characters will be broken up into multiple messages, with a maximum of 153 characters per message.

Messages with one or more UCS-2 16-bit Unicode characters can have up to 670 characters total. Messages that contain Unicode characters and are longer than 70 characters will be broken up into multiple messages, with a maximum of 67 characters per message.

SMS parts
GSM-7 characters Unicode characters
Per part
(a x b)
Per part
(a x c)
1 160 160 70 70
2 153 306 67 134
3 153 459 67 201
4 153 612 67 268
5 153 765 67 335
6 153 918 67 402
7 153 1071 67 469
8 153 1224 67 536
9 153 1377 67 603
10 153 1530 67 670

The Unicode character list is available at https://unicode-table.com/en/blocks/

In countries where mobile networks support long message concatenation, messages with more than one message part are automatically put back together and sent as a single message.

Note: You are charged for each SMS part in a long concatenated SMS.

Tip 1: You can use the SMS length calculator to check for Unicode characters and figure out how many characters are in your text message.

Tip 2: You can use the Unicode to GSM character converter to avoid splitting the SMS into multiple parts and save money on SMS campaigns. The tool will find non-GSM characters and replace them automatically.

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