Why Emojis Affect SMS Length

Emojis are not part of the standard GSM 03.38 character set. Because of this, any SMS containing even one emoji must be sent using Unicode (UCS‑2/UTF‑16) encoding.

This changes how your message is calculated and billed.

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Character Limits With and Without Emojis

Message Type	Encoding	Max Characters per SMS
Standard text (no emojis)	GSM-7	160 characters
Text with at least 1 emoji	UCS‑2/UTF-16	70 characters

If your message exceeds these limits, it will be split into multiple SMS segments and billed accordingly.

Emoji characters can use multiple Unicode code units (and some use many more when combined with modifiers or ZWJ sequences). That means a few emojis can reduce available message length significantly, and the actual segment count may be higher than expected.

Unicode: 70 characters for a single SMS, 67 per segment when split.
GSM‑7: 160 characters for a single SMS, 153 per segment when split.

• A standard letter (e.g., A, B, 1, ?) = 1 code unit
• Emojis can take multiple code units, with some consuming substantially more than others
• ZWJ sequences (used for family emojis, flags, and gendered variants) can consume significantly more code units than simple emojis

Because emoji lengths are variable and can be quite large, adding emojis can significantly reduce how much text fits into a single SMS.

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Important Things to Remember

• Using even one emoji changes the encoding of the entire message.
• A single Unicode SMS can contain up to 70 characters, including emojis.
• If the message exceeds 70 characters, it will be split into multiple SMS segments (concatenated SMS).
• Each segment in a concatenated Unicode message can contain up to 67 characters due to additional headers used to link the parts together.
• Messages longer than 70 characters may be split into multiple segments, which can increase the total cost.

If keeping SMS costs low is important:

• Avoid emojis in high-volume campaigns.
• Keep Unicode messages under 70 characters where possible.
• Always check the message character counter before sending.

You may also refer to our full SMS guide, which contains everything you need to know about sending SMS. SMS User Guide

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