Type or paste your message to see instantly how many characters it has, which encoding it will use and how many SMS (segments) it will be split into. A two-segment message is billed as two SMS, so checking it before you send a bulk SMS campaign avoids unexpected costs.
GSM-7: up to 160 characters in one SMS; longer messages are split into 153-character segments.
How SMS characters are counted
An SMS is measured in bits, not characters: each message carries 140 bytes. How many characters fit depends on the encoding:
- GSM-7: the standard SMS alphabet. Up to 160 characters in a single message.
- UCS-2: used when the text includes any character that is not in GSM-7 (for example á, í, ó, ú or an emoji). Up to 70 characters.
- Concatenated messages: longer texts are split into segments that the phone joins back together. Each segment reserves room for a header, so it holds 153 characters in GSM-7 and 67 in UCS-2.
- Characters that count double: in GSM-7, the symbols ^ { } [ ] ~ | € and the backslash take two positions.
For the full explanation with tables and examples, see our guide on SMS character limits, GSM-7, UCS-2 and segments.
Accents, ñ and emojis: what changes the encoding
In Spanish it is easy to switch from GSM-7 to UCS-2 without noticing. The ñ, Ñ, é, ü and the ¿ and ¡ signs are part of GSM-7. The á, í, ó and ú are not: a single one of them sends the whole message in UCS-2 and drops the limit from 160 to 70 characters.
Emojis and the curly quotes or dashes pasted from a word processor do the same. The «Convert to GSM-7» button replaces those characters with compatible equivalents so the message fits in fewer segments.
On the Grupo Tecnophone platform you choose the encoding of each send, and in GSM-7 unsupported characters are replaced automatically to avoid overcharges. If your message carries a verification code, also see our OTP SMS templates.
Frequently asked questions
How many characters does an SMS have?
Up to 160 characters in GSM-7 or up to 70 in UCS-2. Longer messages are split into segments of 153 (GSM-7) or 67 (UCS-2) characters.
Why does my 100-character message count as two SMS?
Almost always because it includes a character outside GSM-7, such as a vowel with an acute accent or an emoji. That switches the message to UCS-2, whose limit is 70 characters per SMS.
Does ñ count as a special character?
No. The ñ and Ñ are part of the GSM-7 alphabet and take a single position, like any unaccented letter.
Do spaces and line breaks count?
Yes. Every space and every line break takes one position within the message limit.
How much does a multi-segment SMS cost?
Each segment is billed as one SMS. Request a demo and we will show you how your real messages are counted.
Can I use this counter for any carrier?
Yes. The GSM-7 and UCS-2 limits are part of the SMS standard and apply to messages sent to mobile phones in Mexico and other countries.
Sending messages at scale?
With Grupo Tecnophone you send bulk SMS, transactional SMS and OTP codes from a web platform or through the SMS API, with per-message reports and specialized support. Request a demo and we will show you how your real messages would look.