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<mb_strimwidthmb_stristr>
^Multibyte String FunctionsLast updated: Mon, 26 Oct 2026

mb_stripos

(PHP 5 >= 5.2.0, PHP 7, PHP 8)

mb_stripos — Finds position of first occurrence of a string within another, case insensitive

Description

function mb_stripos(
    string $haystack,
    string $needle,
    int $offset = 0,
    ?string $encoding = null
): int|false

mb_stripos() returns the numeric position of the first occurrence of needle in the haystack string. Unlike mb_strpos(), mb_stripos() is case-insensitive. If needle is not found, it returns false.

Parameters

haystack

The string from which to get the position of the first occurrence of needle

needle

The string to find in haystack

offset

The position in haystack to start searching. A negative offset counts from the end of the string.

encoding

The encoding parameter is the character encoding. If it is omitted or null, the internal character encoding value will be used.

Return Values

Return the numeric position of the first occurrence of needle in the haystack string, or false if needle is not found.

Errors/Exceptions

  • If offset is greater than the length of haystack, a ValueError will be thrown.

As of PHP 8.0.0, a ValueError is thrown if encoding is an invalid encoding. Prior to PHP 8.0.0, an E_WARNING was emitted instead.

Changelog

Version Description
8.0.0 needle now accepts an empty string.
8.0.0 encoding is nullable now.
8.0.0 Now throws a ValueError if encoding is an invalid encoding. Previously, an E_WARNING was emitted and false was returned.
7.1.0 Support for negative offsets has been added.

See Also

  • stripos() - Find the position of the first occurrence of a case-insensitive substring in a string
  • strpos() - Find the position of the first occurrence of a substring in a string
  • mb_strpos() - Find position of first occurrence of string in a string


<mb_strimwidthmb_stristr>
^Multibyte String FunctionsLast updated: Mon, 26 Oct 2026