Free Regex Tester Online Tool - 100% Free & No Sign Up | yoyotools

What is a Regex Tester?

A regular expression (regex) is a pattern used to search and match text. This tester lets you write a pattern, choose flags, and instantly see every match highlighted in your sample text, along with captured and named groups.

Features

• Live matching as you type • Toggle the g, i, m, s, u, and y flags • Highlights every match in your text • Lists match positions, numbered groups, and named groups • Clear error messages for invalid patterns

How to Use

1. Type your regular expression 2. Select the flags you want 3. Paste the text to search 4. Review the highlighted matches and group details

Frequently Asked Questions

Which regex syntax does it use?

It uses JavaScript's native RegExp engine, so the syntax and flags match what runs in browsers and Node.js.

Does it support named capture groups?

Yes. Named groups like (?<year>\d{4}) are shown by name in the match details.

Regex Tester

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