Free online regex tester. Test and debug regular expressions with real-time results. Supports global, case-insensitive, multiline, and dotall flags.
Frequently Asked Questions
What is a regular expression (regex)?
A regular expression is a sequence of characters that defines a search pattern. It is used for pattern matching, find and replace operations, and input validation.
What do the flags mean?
Flags modify how the regex is interpreted: g (global) finds all matches, i (case insensitive) ignores case, m (multiline) makes ^ and $ match line boundaries, s (dotall) makes . match newlines.
Can I test my regex in real-time?
Yes! The matches will update automatically as you type your pattern and test text. Green highlights show captured groups.
How do I escape special characters?
Use a backslash before the character. For example, to match a literal dot, use \. instead of just .