SMS character limit is one topic you need to understand if you consider SMS marketing. This is because the character count of your promotional text message content can play a huge role in determining whether your recipients will read or ignore it. 

Technically, a standard text message is 160 characters. However, mobile communication operators allow users to send texts longer than the 160-character limit. This is done through concatenation, where the message content is merged.

In today’s blog post, we will discuss everything you need to know about text messaging character limits, how it’s calculated, and what you can do to ensure you send the right length of SMS messages. So for all that and more, keep reading.

Standard SMS Characters Limit

Short Messaging Service (SMS) has become an integral part of mobile communications. Thanks to this technology, you can send text messages to people, regardless of their location, and as long as they are connected to a mobile network. SMS uses the standard GSM character set, with a limit of 160 characters per message. This limit is a result of the GSM 03.38 7-bit technology that it uses. The characters that can be encoded using this technology are those you can see in the typical QWERTY keyword. 

Unicode SMS Character Limit

Unicode is an international character encoding standard. The beauty of this standard is that it provides a unique number for every character, including symbols and punctuation. This allows you to include non-GSM characters in your text messages and have them sent using top SMS marketing platforms like Textback.ai. 

Many modern software providers use it, and this standard is quite different from the Global System for Mobile (GSM) character set, which is the default you will find on the QWERTY keyboard. Unicode takes up more space than the regular GSM characters, and text messages sent using this format are limited to 70 characters per segment. This is because it contains more characters than the GSM-7 character set. Unicode messages allow you to send emojis as part of your text message content to your audience, something not available in the GSM charset.

Now that we’ve discussed the Unicode character limit, let’s shed some light on the history and basics of this encoding standard. First, the standard is maintained by the Unicode Consortium, and any changes to its character set need to be approved by the consortium and the ISO/IEC 10646. 

Generally, Unicode standard comes in different forms – UTF-32, UTF-16, and UTF-8. These forms work the same way in terms of representing characters. The only difference is in the length of the encodings required per character. UTF-32 requires 32 bits of encoding per character, UTF-16 requires 16 bits, and UTF-8 requires 8 bits. However, the UCS-2 (Universal Coded Character Set 2) is the version of Unicode that is used for text message purposes.

How is SMS Length Calculated

Short messaging service (SMS) is a common form of text messaging and a component available on all modern phones. SMS does not necessarily require internet before messages sent can be received. As long as the recipients are in the network coverage area of their mobile network operator, they will receive messages.

But how exactly is SMS length calculated? Well, it all comes down to the encoding standard used in the message. If your message contains only regular alphabets and digits, the GSM 03.38 encoding will be used, and each message will have 160 characters maximum. Each alphabet or digit will be treated as one character based on the encoding technology.

The main difference comes into play when your message includes Unicode characters. These characters are not present in the GSM character set and are calculated differently. The maximum length of a Unicode SMS message is 70. But you may wonder, why use Unicode characters at all? Well, with Unicode messages, you can add emojis and some special characters in your text, and they will be received by your recipient and readable on mobile phones.

What Counts as a Character in a Text Message?

Now that we’ve explained how message length is calculated, a new question may pop up: “What counts as a character in a text message?” Well, the simple answer is that anything counts as a character. These include letters, digits, special characters, and even spaces. Using the GSM 03.38 encoding technique, a space is counted as a character. This means that if you type in space 160 times in your text message field, you have a one-page SMS message content.

For this reason, if you consider using business messages for promotional purposes, such as SMS marketing, you must plan your content. This way, you can know how many pages your content will take and find a way to use SMS effectively.

Are Special Characters Counted as Multiple Characters in Text Message?

As mentioned in the previous paragraphs, anything and everything counts as characters in text messages. This includes special characters. In the GSM character set, which you see on the QWERTY keyboard, special characters, also called escape characters like the following characters | ^ € {} [ ] ~, count as two characters. So if you are to send only these characters in a text message, you’ll get a character limit of 80 characters per text message.

However, it is worth noting that special characters based on Unicode are encoded differently, as we’ve explained earlier. You can check the Unicode character chart to see all the characters allowed in this type of SMS encoding standard.

How Character Encoding Affects SMS Messages Length?

Character encoding plays a massive role in SMS message lengths. Think about this question – how many characters will be in a message that consists of regular alphabets, digits, symbols, and Unicode messages? Well, they will each be calculated differently.

The maximum number of characters in a Unicode SMS is 70, while for GSM is 160 characters. If you send an emoji as part of your message, it will take up three character counts by the time it is encoded, while regular plain text will take only 1 character. These figures are all together depending on the number of alphabets, digits, symbols, escape characters, and emojis you have in your message.

However, we should point out that regardless of the character count, you can only have one message, two messages, and so on, and not a one-and-a-half message. This means that sending only one alphabet in your text message field is treated as a whole message of 160 characters. And if your message goes 161 characters, it is counted as two messages.

Understanding Message Concatenation

Regarding SMS marketing, the ideal message length should be 160 characters, as we’ve already clarified. However, considering the inclusion of emojis, and special characters, there may be cases where you want to go above this standard limit. So what happens when your message exceeds the 160-character count? 

Well, it becomes a multi-part SMS. In other words, the first 160 characters will be regarded as your first message, and anything after it will become another message. But the good thing is that when you use an SMS marketing platform like Textback.ai, your multiple SMS messages will still be sent as a single message. This is done using a technique called message concatenation.

Concatenation joins separate messages, so the recipient can receive them once. It wouldn’t make sense to receive the first message differently and wait several seconds with the second text message appearing as a different message. However, it is always best to stick to the standard message length of 160 characters wherever possible.

Multi-Part Character Limit

One thing to be aware of with multi-part SMS is that the character limit changes. While a single text message length is 160 characters, a multi-part SMS is 155 characters. The five deducted characters are used for the “user-data headers” (UDH) information, making concatenation possible. 

They are binary structures handled in the system and do not appear in the text message that the recipient will receive. It is worth pointing out that most phone devices and mobile networks will allow users to receive up to 1,000 characters. This translates to seven multi-part SMS, including the UDHs responsible for handling the concatenation.

Multimedia Messages and SMS Character Limits

Multimedia messaging service (MMS) is very different from the standard SMS. MMS allows users to create and send messages with an attached file, picture, video, or GIF. The message goes to the same SMS inbox of a recipient’s phone. However, depending on cellular networks, the message’s data may be limited to a few megabytes.

Due to the nature of MMS, the character limit is quite different. A typical MMS message can take up to an entire size of 5 MB, which can include 10 images and 1,600 characters. But the question is, how are these characters determined? It’s pretty simple, the regular texts in your MMS messages are calculated using the same formula we discussed concerning SMS lengths. The only difference is that it is calculated alongside the data size of the image, video, or GIF you attach.

Creating a Good SMS Marketing Message with Standard Length

We can’t stress this enough—it is advisable to have your message length be the standard 160 characters. The reason is simple, short, and concise messages have a higher chance of being read by your audience. Not just that, it can help you avoid getting your message split when it gets to your recipient. 

But to create a good SMS marketing message content that can convert, you need to plan ahead. Instead of just typing the jargon as it comes to your mind, ask yourself: what do I want to achieve with the SMS marketing campaign? Once you have a clear objective, you can compose your messages following the industry’s SMS best practices. 

For example, consider going for short trackable links instead of including long URLs that make readability poor. This will also help you avoid your message character length getting high. We also recommend you include a CTA in your SMS marketing messages, which should be within the standard 160 characters. You can learn more about how to create good SMS marketing messages at Textback.ai.

Characters to Avoid in Your SMS Marketing Campaigns

You should consider avoiding some characters if you plan to send business messages in your SMS marketing campaigns. Every business wants to minimize expenses and maximize returns. So, applying this in the SMS marketing area, you’ll most likely want to keep your text messages to one or two SMS segments. If you fail to do that and compose long messages, your messages will split into multiple segments (multi-part SMS), which automatically translates to increased SMS costs and bills.

One of the main reasons the character length of a message can increase drastically is when you are using accented characters. These are alphabets or symbols with dielectric marks over or under them. They are counted as two or more characters in text messages, meaning you can easily go above the 160 characters that are the single standard message length. By avoiding these characters where possible, you can end up having more space for your message content and not have to overspend on your text marketing campaigns.

SMS Character Limits in Different Languages

While English is a generally accepted language, there may be situations where you want to send SMS in other languages. How, then, are the characters calculated? With Unicode, it is possible to represent characters in most languages. The only thing to be aware of is that the messages will take up to a length of 70 characters per SMS.