PHP Multibyte String Functions – Complete List with Examples

The mb_* functions come from the mbstring extension, which is enabled in almost every PHP install. They count and cut by characters, so accented letters and non-Latin scripts work correctly. The encoding defaults to UTF-8.

Name	Description	Since
`mb_strlen()`	Return the number of characters in a string, counting é or 日 as one character. The UTF-8-safe version of strlen().	4.0
`mb_substr()`	Return part of a string by character position, so multibyte characters are never cut in half. The UTF-8 version of substr().	4.0
`mb_strtolower()`	Convert a string to lowercase, including letters outside ASCII such as É, Ü and Cyrillic. The Unicode-aware strtolower().	4.3
`mb_strtoupper()`	Convert a string to uppercase, including letters outside ASCII such as é, ß and Cyrillic. The Unicode-aware strtoupper().	4.3
`mb_convert_case()`	Change the case of a string with Unicode rules: upper, lower, title case or case folding for comparisons.	4.3
`mb_strpos()`	Find the character position of the first occurrence of a substring in a multibyte string. Returns false if not found.	4.0
`mb_str_split()`	Split a multibyte string into an array of characters, or of chunks of n characters. The UTF-8-safe str_split().	7.4
`mb_str_pad()`	Pad a multibyte string to a given length in characters, on the left, right or both sides. Added in PHP 8.3.	8.3
`mb_trim()`	Strip whitespace from both ends of a string, including Unicode spaces such as the non-breaking space. Added in PHP 8.4.	8.4
`mb_ucfirst()`	Make the first character of a string title case, including letters such as é or ı. Added in PHP 8.4.	8.4

Name

Description

Since

mb_strlen()

Return the number of characters in a string, counting é or 日 as one character. The UTF-8-safe version of strlen().

4.0

mb_substr()

Return part of a string by character position, so multibyte characters are never cut in half. The UTF-8 version of substr().

4.0

mb_strtolower()

Convert a string to lowercase, including letters outside ASCII such as É, Ü and Cyrillic. The Unicode-aware strtolower().

4.3

mb_strtoupper()

Convert a string to uppercase, including letters outside ASCII such as é, ß and Cyrillic. The Unicode-aware strtoupper().

4.3

mb_convert_case()

Change the case of a string with Unicode rules: upper, lower, title case or case folding for comparisons.

4.3

mb_strpos()

Find the character position of the first occurrence of a substring in a multibyte string. Returns false if not found.

4.0

mb_str_split()

Split a multibyte string into an array of characters, or of chunks of n characters. The UTF-8-safe str_split().

7.4

mb_str_pad()

Pad a multibyte string to a given length in characters, on the left, right or both sides. Added in PHP 8.3.

8.3

mb_trim()

Strip whitespace from both ends of a string, including Unicode spaces such as the non-breaking space. Added in PHP 8.4.

8.4

mb_ucfirst()

Make the first character of a string title case, including letters such as é or ı. Added in PHP 8.4.

8.4