/.*/
Regex
Test and debug regular expressions with real-time matching.
About Regex
Regular expressions are one of the most powerful — and most confusing — tools in a developer's toolkit. A single misplaced quantifier can turn a working pattern into a catastrophic backtracking nightmare. Testing regex patterns against sample text with immediate visual feedback is the fastest way to get them right.
Our Regex Tester shows matches highlighted in real-time as you type. See all matched groups, their positions, and captured subgroups. Toggle flags (global, case-insensitive, multiline, dotAll) with a click. The tool uses JavaScript's native RegExp engine, so the behavior matches exactly what you'll get in your browser-based application.
FAQ
Which regex flavor does this tool use?
The tool uses JavaScript's built-in RegExp engine, which supports ECMAScript regex syntax including features like named groups, lookbehind assertions (in modern browsers), and Unicode property escapes.
Why does my regex work here but not in Python/Java?
Different languages have different regex engines with slightly different syntax and features. JavaScript regex is ECMAScript-based. Python uses the re module, Java uses java.util.regex — each has unique syntax for things like lookbehinds, atomic groups, and possessive quantifiers. Always verify your pattern in the target language.