What is the maximum length of a message?

It depends on whether the message uses diacritics or not. The capacity of a standard message is 160 characters. If the message contains diacritics, its capacity is only 70 characters.

To deliver a longer text to the recipient's phone as well, there is a way to split a longer message into separate SMS messages that are reassembled on the recipient's phone. In such a case the message capacity is reduced from 160 to 153 characters for messages without diacritics and from 70 to 67 characters for messages with diacritics) so that each SMS can carry information about how the SMS messages should be joined back into one message (their order and total count) on the recipient's phone.

Number of characters in individual SMS parts

Messages without diacritics (GSM):

SMS with diacritics (UCS-2):

How long should an SMS message be?

160 characters is usually sufficient. SMS messages should always be to the point and have a clear message and a call to action/goal. Use AI to help you optimize the length of your message.

Many customers try to fit all the information into an SMS and use up all 160 characters at any cost. However, some tests have shown that even a simple message with an emoji, information about the discount amount and a link can work more effectively.

GSM character set

The GSM standard is more than 30 years old and therefore carries certain specifics that are relatively complicated and hard to understand in today's world. One such specific is the SMS character set and the associated message length and capacity.

The GSM 03.38 character set is the standard character set for text messages in GSM mobile phones. All GSM phones and network elements support the 7-bit GSM alphabet. The basic GSM character set contains the letters A to Z (uppercase and lowercase), digits, special symbols and a few symbols from the Greek alphabet. These are the following characters: @, £, $, ¥, è, é, ù, ì, ò, Ç, , Ø, ø, , Å, å, Δ, _, Φ, Γ, Λ, Ω, Π, Ψ, Σ, Θ, Ξ, , Æ, æ, ß, É, , !, ", #, ¤, %, &, ', (, ), *, +, ,, -, ., /, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, :, ;, <, =, >, ?, ¡, A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, Ä, Ö, Ñ, Ü, §, ¿, a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z, ä, ö, ñ, ü, à.

An interesting example is this message: "Hi Renée, your café order is ready for pick-up.". It can be sent as a single SMS message even though it contains the "é" character. That character is part of the standard GSM character set, so the message does not have to be encoded as Unicode. Similarly practical is that the @ character, brackets, quotation marks, etc. do not reduce the message capacity.

Remember that even if you use just a single special character, the whole message will always switch to Unicode encoding and the SMS capacity will be reduced to 70 characters.

Special characters

Some characters in the extended GSM 03.38 table can only be used at the cost of two characters. The GSM character set uses 7-bit encoding of the alphabet, but these special characters (sometimes also referred to as "escape characters" or characters that are part of the so-called "extended character set") require 14 bits to encode, so they take up two characters. These are the following characters: |, ^, €, {, }, [, ], ~, \.

Unicode symbols

Compared to the GSM character set, Unicode encoding supports a huge range of languages and symbols. However, if your text message contains a symbol that is not in the 7-bit alphabet, UCS-2 encoding must be used. This type of encoding takes up a lot of space, which reduces the number of characters allowed in a message to 70.

Unicode is a standard for encoding, processing and representing text expressed in many of the world's writing systems. The latest list of Unicode symbols contains more than 120,000 characters from several symbol sets and 129 historical and modern scripts.

Using emoji in SMS

Emoji are special types of symbols that can be used in text messages. They are encoded using Unicode and can be displayed by most modern phones and devices.

Please note that the information about the number of characters and the number of SMS messages is based on the settings of this page and also your browser. In practice, it can theoretically happen that the number of characters differs due to the use of special characters that the calculation on this page did not account for. For that reason, please consider the information provided here as approximate. 100% confirmation and control of message length is guaranteed by our SMS API, or you can contact us.