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StringLength—Wolfram Documentation

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StringLength["string"]

gives the number of characters in a string.

Details
Details and Options Details and Options
Examples  
Basic Examples  
Scope  
Applications  
Properties & Relations  
Possible Issues  
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StringLength

StringLength["string"]

gives the number of characters in a string.

Details

  • StringLength counts special characters such as as single characters, even if their full names involve many characters.
  • StringLength[{s1,s2,…}] gives the list of lengths of each of the si.
  • StringLength[BioSequence["type","seq"]] will give the length of the string "seq".

Examples

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Basic Examples  (1)

Find the number of characters in a string:

Wolfram Language code: StringLength["tiger"]

Scope  (4)

Find lengths of all strings in a list:

Wolfram Language code: StringLength[{"cat", "dog", "fish", "coelenterate"}]

StringLength treats special characters just like ordinary ones:

Wolfram Language code: StringLength["◆αβγ⟷𝒜ℬ𝒞↵"]

Newlines count as one character:

Wolfram Language code: "ab cd"
Wolfram Language code: StringLength[%]

Find the length of a biomolecular sequence:

Wolfram Language code: StringLength[BioSequence["DNA", "CTTCGACTACCAGCGGGTCGAACGGCCCATGGCATC"]]

Applications  (1)

Find the growth rate of a string substitution system:

Wolfram Language code: NestList[StringReplace[#, {"A" -> "AB", "B" -> "A"}]&, "A", 5]
Wolfram Language code: StringLength[%]

Properties & Relations  (2)

The empty string has zero length:

Wolfram Language code: StringLength[""]

StringLength counts the underlying character codes, not selectable characters:

Wolfram Language code: StringLength["👨‍🍳"]

The length is equivalent to the length of the list returned by ToCharacterCode:

Wolfram Language code: Length[ToCharacterCode["👨‍🍳"]]

It is also equivalent to the length of the list returned by Characters:

Wolfram Language code: Length[Characters["👨‍🍳"]]

Possible Issues  (2)

Formatting constructs are included in giving lengths of formatted strings:

Wolfram Language code: FullForm["red"]
Wolfram Language code: StringLength["red"]

StringLength counts every character as length 1, regardless of the length of its full name:

Wolfram Language code: FullForm["αβγ"]
Wolfram Language code: StringLength["αβγ"]
Wolfram Research (1988), StringLength, Wolfram Language function, https://reference.wolfram.com/language/ref/StringLength.html (updated 2020).

Text

Wolfram Research (1988), StringLength, Wolfram Language function, https://reference.wolfram.com/language/ref/StringLength.html (updated 2020).

CMS

Wolfram Language. 1988. "StringLength." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2020. https://reference.wolfram.com/language/ref/StringLength.html.

APA

Wolfram Language. (1988). StringLength. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/StringLength.html

BibTeX

@misc{reference.wolfram_2026_stringlength, author="Wolfram Research", title="{StringLength}", year="2020", howpublished="\url{https://reference.wolfram.com/language/ref/StringLength.html}", note=[Accessed: 14-November-2026]}

BibLaTeX

@online{reference.wolfram_2026_stringlength, organization={Wolfram Research}, title={StringLength}, year={2020}, url={https://reference.wolfram.com/language/ref/StringLength.html}, note=[Accessed: 14-November-2026]}