Learn how to use Regex Tester with this step-by-step guide. Includes examples and tips.
Type your regular expression.
Enter text to test against.
View highlighted matches and capture groups.
The tool uses JavaScript (ECMAScript) regular expressions, which are the standard for web development and Node.js applications. This includes support for lookahead, lookbehind (ES2018+), named capture groups, and Unicode property escapes. Patterns written here will work directly in JavaScript, TypeScript, and most modern programming languages with compatible regex engines.
All standard JavaScript regex flags are supported: global (g) for multiple matches, case-insensitive (i) for ignoring letter case, multiline (m) for treating each line as a separate string boundary, dotAll (s) for matching newlines with dot, unicode (u) for full Unicode support, and sticky (y) for matching at exact positions.
Yes, all capture groups are displayed in detail — both numbered groups (parentheses) and named groups (?<name>...) are shown with their matched content and position. This makes it easy to build and debug complex extraction patterns for parsing structured text, log files, and data strings.
