preg_replace Online
Test PHP's preg_replace() function online using real PHP 8.2. Replace strings using regular expressions. Perfect for testing regex patterns and replacements.
preg_replace(string|array $pattern, string|array $replacement, string|array $subject, int $limit = -1, int &$count = null): string|array|null Pattern (Regex)
Enter your regex pattern (include delimiters like /pattern/)
Replacement
Enter the replacement string (can use $1, $2 for capture groups)
Subject (Text to Replace)
Enter the text where replacements will occur
PHP Code
This is the actual PHP code that will be executed
Common Replacement Patterns
preg_replace() Function Guide
About preg_replace()
This tool runs actual PHP 8.2 code on our server using Docker containers. The preg_replace() function performs regex-based search and replace operations. It's perfect for complex string transformations, data cleaning, and pattern-based replacements.
- Replaces all matches by default
- Supports capture groups ($1, $2, etc.)
- Can use backreferences in replacement
- Returns modified string
- Count parameter tracks replacements
Backreferences & Captures
$0- Full matched text$1, $2, ...- Capture group 1, 2, etc.${1}- Alternative syntax (clearer)\\1, \\2- Legacy backreferences
⚠️ Security: Be cautious with user input in patterns. Use preg_quote() to escape special regex characters if needed.
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