Regex•100% Client-Side

Regex Tester Online

Write and test regular expressions in real-time. Inspect matches, character counts, capture groups, and validation patterns client-side. Includes syntax error tracking.Reference Spec: MDN Regular Expressions Reference Guide→

//
Test Text String
Matches List0 Matches Found

No matches found.

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Frequently Asked Questions (Regex Tester)

What is a Regex Tester?

A Regex Tester is an interactive editor that allows you to write Regular Expressions (Regex) and test them against custom target strings. It validates the expression syntax and displays matching substrings, start/end index boundaries, and captured groups.

What do the regex flags (g, i, m, s) do?

Flags modify the regex engine search rules: 'g' (global) finds all matches instead of stopping at the first; 'i' (ignore case) performs case-insensitive comparisons; 'm' (multiline) treats start/end anchors (^/$) as line borders rather than string boundaries; 's' (dotAll) allows the dot (.) token to match newline characters.

Can I use capture groups?

Yes. Any capturing group defined with parentheses () in your expression is isolated and rendered as sub-items in the matches inspector table, detailing group values and indexes.

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