Unicode and PCRE
Add the u modifier to handle multibyte Unicode characters correctly. Use \p{...} for Unicode property classes.
PHP
Advanced
5 min read
Unicode Regex in PHP
Example
<?php
// Match Unicode letters (any script)
preg_match("/^\p{L}+$/u", "Привет"); // matches Russian
preg_match("/^\p{L}+$/u", "مرحبا"); // matches Arabic
preg_match("/^\p{L}+$/u", "Hello"); // matches English
// Match Unicode digits (includes Arabic-Indic numerals)
preg_match("/\p{Nd}+/u", "١٢٣"); // Arabic-Indic digits
// Count characters correctly (mb_ functions)
echo mb_strlen("café"); // 4 (not strlen: 5 bytes)
// Unicode word boundary issues
preg_match("/\bjava\b/iu", "JavaScript"); // may not work as expected with Unicode Pro Tip
The /u modifier makes . match Unicode characters correctly — without it, multibyte characters are treated as multiple bytes.