Regex Generator & Tester
Test regular expressions, inspect matches and groups, replace text, or start from common patterns.
Processing happens locally in your browser. Your files and inputs are not uploaded to our servers.
How to use Regex Generator & Tester
- Enter a pattern, select flags, and add test text.
- Review highlighted matches, groups, and match count.
- Optionally enter replacement text or load a common starter pattern.
What Regex Generator & Tester does
A regular expression describes text patterns. The tester uses JavaScript RegExp behavior, highlights matches, lists indices and capturing groups, and can preview replacement output.
Examples
- Find email-like strings in test data.
- Capture year, month, and day from ISO-style dates.
- Replace repeated whitespace with a single space.
Frequently asked questions
Is my input uploaded?
No. This tool processes its input locally in your browser. Normal page requests do not include the contents you enter or select.
Are the helper patterns universally correct?
No. Email, phone, date, and URL rules vary by context. The included patterns are practical starting points that should be adapted and tested.
Will it work in every browser?
The tool uses modern browser APIs. Current Chromium, Firefox, and Safari releases provide the best support; the page displays a clear error when a required capability is unavailable.