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Free Online SMS Length Calculator

Welcome to our SMS length calculator, a user-friendly tool designed to count the number of characters in your text message and offer deeper insights into its composition.

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Encoding7bit
SMS parts0
Chars used0
Chars in SMS160

Detailed view

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Legend

  Regular 7bit character, present in GSM charset
ESC Escape character 0x1B; required to access |^€{}[]~ characters
  User Defined Header (UDH) of the message. Required for multipart sms
  Character present in GSM charset, encoded as Unicode character
  Character not present in GSM charset, forces to use Unicode encoding

Here’s a quick rundown of everything this tool will tell you.


  • Encoding: Tells you the type of encoding that will be applied to your SMS. Depends on what type of characters you’ve used
  • SMS parts: Tells you the number of parts (segments) your SMS will be split into for transmission
  • Chars used: Tells you how many characters long your text is
  • Chars in SMS: Tells you the maximum number of characters you can use. This will be 160 or 70 characters (153 or 67 for multipart messages), depending on the type of encoding

For in-depth analysis, check out the “Detailed view” section. It visualizes your message’s encoding so you can see how it’s segmented in real time, as you’re typing your message in the text box above. The “Legend” is a quick guide for the different types of characters that might pop up in the detailed view. For an even richer explanation, keep scrolling!

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Why SMS messages have a character limit

SMS messages need to fall within a specific number of characters because of the way they’re transmitted. There are certain technical constraints. The limit makes sure messages are delivered quickly and without taking up too much bandwidth, helping the network run smoothly for everyone.

What does message encoding even mean?

Message encoding is the process of converting human-readable text into a format that’s suitable for transmission over cellular networks. There are mainly two types of SMS encoding.

  • 7-bit encoding, which is standard for English and other Latin-based languages
  • Unicode encoding, used for a broader range of characters and languages
7-bit encoding (GSM-7)
Unicode encoding (USC-2/UTF-16)

7-bit encoding (GSM-7)

7-bit encoding, or GSM-7, is the default encoding format for SMS, supporting the GSM 03.38 character set. This encoding allows up to 160 characters in a single message.

Some 7-bit characters are not in the standard set but are part of the GSM 03.38 Extension Table. These need to be prefixed with an escape character (ESC, 0x1B).

\         |         ^         €         {         }         [         ]         ~

Characters from the extension table don’t reduce the text message character limit, but they do each count as two characters because of the prepended escape character. This ensures compatibility while managing message length efficiently. Here’s a detailed view of what such a character would look like behind the scenes:

Unicode encoding (USC-2/UTF-16)

If your messages contain characters beyond the GSM 03.38 alphabet, such as emojis or non-Latin scripts, Unicode (USC-2 or UTF-16) encoding takes over.

UCS-2 supports a much wider range of characters and languages than the very limited 7-bit encoding. But alas, it also requires more data size per character. This reduces the already compact SMS length from 160 to 70 characters. So you’ll have to put some extra thought into your SMS body to avoid unnecessary segmentation.

Multipart SMS messages

When a text message sent through an SMS API, for example, exceeds the 160-character limit (or the 70-character limit, in the case of UCS-2 encoding), it’s automatically broken into pieces. It is now a multipart message, aka multisegment message.

The different parts of the same message are sent to the handset, and charged separately, too. For instance, an SMS split into three segments will be charged the same as three SMS messages. So, it’s important that you use our text message segment calculator to make sure you don’t exceed the limit and pay more than you planned.

If your message is unavoidably long, there’s a process in place for seamless concatenation, which keeps your message coherent across multiple parts and ensures that the segments are delivered and received in the right order.

An extra bit of info called the User Data Header is added before each segment. A UDH states the order and message each part belongs to, like an identifier. Here’s what it would look like in the detailed view.

Pretty neat, but there’s a catch. Since the UDH itself also occupies space within the message, the overall length of each 7-bit segment is shortened to 153 characters (67 characters for UCS-2) for multipart SMS messages.


Regular SMS
Multipart SMS
7-bit
160 chars
153 chars
Unicode
70 chars
67 chars

For optimal deliverability, multiple communication experts here at Messente recommend that you keep each SMS under 160 characters. The greater the number of multipart messages, the higher the chances of something going wrong in transmission.

Tips for new users

Using our SMS character counter is pretty straightforward.
Step 1: Enter text
Step 2: See special characters
Step 3: See encoding type
Step 4: See number of segments

Step 1: Enter text

Simply enter your text, and the tool will display the number of characters.

Step 2: See special characters

It will also flag special characters so that you can remove them to save space and per SMS cost.

Step 3: See encoding type

You can see the encoding type, too, in case you or your recipient are using an SMS app or phone that is limited in its functionality and doesn’t support Unicode, for instance.

Step 4: See number of segments

If your message exceeds the single-part limit, you can try adjusting the message length, such as by removing fluff or special characters, without losing value or omitting any important details.

And if it still doesn’t fit? Nothing to worry about. It’s okay to send messages in more than one part. Concatenated SMS FTW!

Adding emojis to your messages

Incorporating emojis can liven up your SMS communication, but, due to Unicode encoding, the character limit gets slashed to 70 per message. If you’re using our API, you can easily add emojis, but make sure you don’t go overboard – you need to maintain message effectiveness without exceeding the limit unnecessarily.

For more info, check this out: How to Use Emojis in Text Messages


Basic best practices for SMS marketing

If you’re new to SMS marketing, here are some important pointers.

  • Keep messages concise, clear, and to the point.
  • Schedule your SMS messages for times when recipients are most likely to engage.
  • Use recipient names and personalized content to boost impact and get better responses.
  • To optimize your subscriber database, use our free carrier lookup tool, phone number validator, or similar applications. These can help you validate phone numbers and fetch location and carrier info, leading to better delivery rates and lower costs.
  • Review campaign performance regularly and adjust your marketing strategy accordingly. Our SMS ROI calculator can help with better campaign planning.
  • Read up on local and global SMS marketing laws and regulations, especially about opt-ins and opt-outs.

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