Which regex flavour is supported?

The tester uses JavaScript regular expressions. Patterns compatible with ECMAScript will work here.

Use browser bookmarks or copy the pattern JSON export for future reference.

Is there a dark mode?

Yes, the tester respects the site theme, making late-night debugging easier.

Does the tool store my data?

Regex processing stays in the browser, but patterns, test text, and replacement text are saved in local storage. Share links include that state in the URL fragment.

Browser tool

Test Regular Expressions with Live Feedback

Write expressions, test against sample text, view matches, and export results as JSON or CSV for your automation scripts.

Pattern

Examples:

Test text

Replace

Cheat-sheet

Basics

. any, \\d digit, \\w word, \\s whitespace

Quantifiers

+ one+, * zero+, ? optional, {m,n}

Anchors

^ start, $ end, \\b word boundary

Groups

( ), (?: ), (?<name> )

Lookarounds

(?= ), (?! ), (?<= ), (?<! )

Matches: 0

Enter a pattern (e.g., \\d+).

Quick instructions

1
Enter your pattern
Type or paste your regex in the pattern field and enable relevant flags.
2
Provide sample text
Paste the data you want to test or use built-in samples to verify the pattern quickly.
3
Review matches
Check highlighted matches, capture groups, and counts to confirm the regex behaves as expected.
4
Export results
Copy matches or replacements to use in scripts, ETL pipelines, or quick clean-up tasks.

Examples & tips

Normalize phone numbers

Use capture groups to format international phone numbers consistently.

Extract Markdown links

Match [text](url) patterns and export results to audit outbound linking.

Clean analytics exports

Strip query parameters or hash fragments from URLs before loading them into dashboards.

Useful details

Review capture groups carefully—unexpected matches usually mean you need non-greedy quantifiers.
Pair with the Data Converter to reshape matched data into CSV or JSON outputs.

About this tool

Regular expressions are powerful but unforgiving. Our tester provides instant feedback, capture breakdowns, and replacement previews so you can build patterns confidently.

Because everything runs locally, you can debug logs, customer data, or proprietary templates without risk.

Questions

Which regex flavour is supported?: The tester uses JavaScript regular expressions. Patterns compatible with ECMAScript will work here.
Can I save patterns?: Use browser bookmarks or copy the pattern JSON export for future reference.
Is there a dark mode?: Yes, the tester respects the site theme, making late-night debugging easier.
Does the tool store my data?: Regex processing stays in the browser, but patterns, test text, and replacement text are saved in local storage. Share links include that state in the URL fragment.