How do I use the Regex Tester?

Enter a regex pattern and enable the flags you need, such as global or multiline matching. Paste or type sample text into the test string area to see matches highlighted instantly. Review the match table to inspect each full match, index position, and captured group output. Load a common snippet from the sidebar when you want a quick starting point for email, URLs, dates, or other patterns. Refine the pattern until the highlighted results and groups match the exact text you want to capture.

Is the Regex Tester free?

Yes, the Regex Tester is completely free. It runs entirely in your browser with no signup, no download, and no data sent to any server.

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Regex Tester

Test regex patterns with live match highlighting, capture groups, flags, and reusable developer snippets.

regex testerregular expression testercapture groupsregex matcherdeveloper regex tool

Regex pattern

g global i ignore case m multiline s dotAll

Test string

Type or paste text to see highlighted matches and capture groups update instantly.

Highlighted matches

0 matches

No matches yet.

Match groups

0 captures

Common regex snippets

Click to load

How to use

Test patterns with live highlighting and capture groups

1 Enter a regex pattern and enable the flags you need, such as global or multiline matching.
2 Paste or type sample text into the test string area to see matches highlighted instantly.
3 Review the match table to inspect each full match, index position, and captured group output.
4 Load a common snippet from the sidebar when you want a quick starting point for email, URLs, dates, or other patterns.
5 Refine the pattern until the highlighted results and groups match the exact text you want to capture.

A browser-based regex tester is useful whenever you need quick feedback while building validation rules, content parsers, or text cleanup workflows. This version shows live highlighted matches inside the sample text so you can verify whether your expression is too broad, too narrow, or missing edge cases. You can also toggle the most common JavaScript flags without leaving the page, which makes it easier to understand how global, case-insensitive, multiline, and dotAll behavior changes the result.

The match groups table is especially helpful when you are working with capture groups for replacements, routing rules, parsing, or developer tooling. Each successful match shows its index, full value, and any captured segments so you can confirm your groups line up with the text you actually need. The snippet sidebar adds fast examples for common tasks such as email validation, URL scanning, date matching, number extraction, and hashtags, making the tool practical for both learning and day-to-day development.

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