Regex Tester

Test and debug JavaScript regular expressions with real-time pattern matching, capture group inspector, and flag controls.

How to Use Regex Tester

Enter your regular expression pattern in the regex input field.

Select flags such as Global (g), Case-Insensitive (i), or Multiline (m).

Paste your sample test text into the test area.

View live highlighted matches, match count, and extracted capture groups.

Evaluates regular expressions against test text using the browser's native RegExp engine. Highlights matching substrings and indexes capture groups.

Building validation patterns for emails, phone numbers, and URLs.

Crafting regex replacements for log parsing and text cleanup.

Learning regex syntax with immediate visual feedback.

Privacy & Local-First Processing

All regex evaluation runs client-side in the browser. Zero test strings or patterns are uploaded.

It supports standard ECMAScript / JavaScript regular expressions, including lookahead, lookbehind, and named capture groups.