Write a regular expression, paste sample text, and see every match highlighted live along with capture groups and named groups. Uses your browser's own JavaScript regex engine.
Getting started
Enter your regular expression pattern without the surrounding slashes.
Toggle the flags you need — global, case-insensitive, multiline, dot-all and Unicode.
Paste sample text into the test area.
Matches highlight live, with a breakdown of capture groups for each one.
Why it helps
Uses your browser's native engine, so behaviour matches JavaScript exactly rather than approximating it.
Supports every modern feature including named capture groups, lookbehind and Unicode property escapes.
Invalid patterns report the syntax error immediately rather than silently matching nothing.
Group breakdowns show what each capture actually caught, which is where most regex bugs hide.
In practice
Building a validation pattern for an email, postcode or phone number field.
Working out the right pattern for a bulk find-and-replace before running it.
Debugging a pattern that matches too much or too little.
Learning regular expressions with immediate visual feedback.
Everything people ask most about the regex tester, answered plainly.
Keep exploring
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