Check how many SMS segments your message uses before sending it. Paste or type your text to see its character count, encoding, and segment count instantly. Enable Smart Encoding to calculate with compatible character replacements, or use Optimize Message to apply replacements to your text.
The bar measures encoding units against total segment capacity. Some characters use two units. Characters count measures Unicode code points after Smart Encoding, so a combined emoji can count as several characters.
Smart Encoding replaces characters such as curly quotes (“ ”) with straight quotes (" ") for calculation. Optimize Message applies replacements to your text and also simplifies accented Latin letters where possible.
- Encoding
- GSM-7
- Segments count
- 0
- Characters count
- 0
Estimates use standard SMS limits: 160/153 units for GSM-7 and 70/67 for UCS-2. Sender and carrier limits can differ, including US/Canada toll-free multipart limits of 152/66. Your message is processed entirely in your browser.
Frequently Asked Questions
What is an SMS segment?
An SMS segment is one part of a text message. Longer messages are split into multiple segments, which the recipient’s phone usually combines into one message.
How many characters fit in one SMS?
A single SMS supports up to 160 GSM-7 encoding units or 70 UCS-2 units. Longer messages typically allow 153 or 67 units per segment because some space is needed to join the segments together. Certain characters use more than one unit.
What is the difference between GSM-7 and UCS-2?
GSM-7 supports Latin letters, numbers, common punctuation, and some other characters. Messages containing characters outside this set, such as many non-Latin letters and emoji, require UCS-2 encoding, which has a smaller capacity per segment.
Why does adding one character increase my segment count?
A character outside GSM-7 can change the encoding of your entire message to UCS-2. This reduces the available capacity per segment, so even a single emoji or curly quotation mark can increase the segment count.
What does Smart Encoding do?
Smart Encoding replaces certain characters, such as curly quotes, with compatible alternatives when calculating your results. It leaves the text in the Message field unchanged. If no compatible replacements are found, switching it on will not change your results.
What does Optimize Message do?
Optimize Message applies compatible replacements directly to your text and simplifies some accented Latin letters. Characters it cannot convert remain unchanged. Review the result before using it, or select Undo to restore your original message.
Which Encoding option should I choose?
Choose Auto to detect the appropriate encoding for your message. Select GSM-7 to check whether your text fits that character set, or UCS-2 to calculate its segment count using Unicode encoding.
Is my message sent to a server?
The calculator processes your message in your browser. It does not send your text to an external service or save it on our server.
Will the segment count always match my SMS provider?
The calculator estimates segments using standard SMS limits. Some sender types, carriers, and provider-specific message processing can produce different results.