SMS Character Counter
Type your SMS and instantly see character count, encoding type (GSM‑7 or Unicode), number of SMS segments, and how many characters remain. Avoid surprise billing.
Start typing to see character count and SMS segments
SMS Encoding Reference
| Encoding | Single SMS | Per Segment (multi) | When used |
|---|---|---|---|
| GSM-7 | 160 chars | 153 chars | Latin alphabet + basic symbols only |
| Unicode (UCS-2) | 70 chars | 67 chars | Emoji, Arabic, Chinese, Hindi, etc. |
✦ NumberOTP
Need to receive SMS OTP codes programmatically?
NumberOTP provides real virtual numbers in 150+ countries with instant SMS delivery and a developer API. Integrate in minutes.
$0.10 free credits on signup · No card required · Numbers from $0.01
Frequently Asked Questions
How many characters fit in one SMS?
It depends on the encoding. GSM-7 (Latin alphabet + common symbols): 160 characters. Unicode/UCS-2 (emoji, Arabic, Chinese, etc.): 70 characters. For messages longer than these limits, the carrier splits into segments of 153 (GSM-7) or 67 (Unicode) characters each, with headers consuming the difference.
What is GSM-7 encoding?
GSM-7 is a 7-bit character set used in mobile networks. It covers the Latin alphabet, digits, and common symbols. Using only GSM-7 characters maximises your message length (160 chars/segment). Some characters like { } [ ] ~ ^ | € count as 2 GSM-7 characters because they use an extension table.
Why does one emoji cut my message from 160 to 70 characters?
Emoji and many non-Latin characters (Arabic, Chinese, Hindi, etc.) are not in GSM-7. Adding even one such character forces the entire message to switch to Unicode (UCS-2) encoding, which uses 16 bits per character instead of 7 — cutting capacity to 70 characters per segment.
What is a multi-part SMS?
When a message exceeds one segment limit (160 GSM-7 / 70 Unicode chars), it is split into multiple parts. Each part carries a User Data Header (UDH) that uses 7 characters (GSM-7) or 3 characters (Unicode), reducing the payload to 153 or 67 chars per part. Carriers charge per segment.
Why do I need to test SMS messages?
Unexpected encoding switches and multi-part splitting are leading causes of SMS cost overruns and failed delivery. Testing before sending — especially for OTP and marketing messages — ensures you pay only for what you expect.