What Is the SMS Text Length?

If you’ve ever sent a text message and wondered why it got split or why your SMS bill looked higher than expected - you’re not alone. SMS text length has real-world implications for businesses, especially when it comes to message delivery and cost.

Here’s everything you need to know about how SMS character limits work, and how to avoid surprises when sending text messages.

Standard SMS Character Limits

A single SMS supports up to:

• 160 characters using the GSM-7 character set

• 70 characters if your message includes Unicode characters (like emojis or non-Latin scripts such as Arabic or Chinese)

But once your message goes over these limits, things get a bit more complex.

What Happens When You Exceed the Limit?

Most modern networks support concatenation - this means messages longer than 160 or 70 characters are split into smaller pieces called segments, then stitched back together on the recipient’s phone.

However, each segment is treated (and billed) as an individual message.

• GSM-7 segmented messages are split into parts of 153 characters

• Unicode (UCS-2) segmented messages are split into parts of 67 characters

Why not the full 160 or 70? Because a few characters are reserved for the technical “header” that helps reassemble the full message on the other end.

Example: A 161-character GSM message becomes 2 segments -153 characters in the first, 8 in the second.

Hidden Characters Can Cost You

Many businesses unintentionally trigger Unicode encoding. A single special character - like a curly quote (“ ”), a currency symbol (₹), or an emoji - can switch the encoding from GSM-7 to UCS-2, instantly shrinking your message limit.

To avoid this, always check your content before sending. Small formatting differences (especially when copying from Word or web pages) can silently change your character set.

Try our SMS Message Length Calculator to check if your message is safe or if it risks getting segmented or re-encoded.

Best Practices for SMS Length and Encoding

• Stick to GSM characters when possible

• Avoid emojis and smart punctuation unless needed

• Keep it concise - ideally under 160 characters

• Use a segment checker tool before sending

Why 160 Characters?

The 160-character SMS limit wasn’t chosen randomly. It dates back to 1985, when engineers defined SMS as a service that could "ride along" on existing mobile network infrastructure. They allocated 140 bytes of space for messages, which equals 160 characters using 7-bit encoding.

Stay Efficient, Stay Connected

Understanding how SMS text length and encoding work helps you save money and deliver a better customer experience. Whether you’re running marketing campaigns or sending alerts, staying within the character limit or at least managing segments - can make a big difference.