Regex Tester
Test regular expressions with flags, highlighted matches and examples.
Matches and errors will appear here.
Processing runs locally in your browser. Toolexa does not upload or permanently store your input.
About Regex Tester
Regex Tester is an interactive developer utility for checking regular expressions against sample text directly in the browser. Enter a pattern without surrounding slashes, choose common flags such as global, case-insensitive, multiline or dot-all, and inspect every match in a highlighted preview. The result summary shows match count, matched text and character positions, while capturing groups are included when the expression defines them. Built-in examples for email addresses, URLs, numbers and repeated whitespace provide quick starting points for common validation and search tasks. Invalid patterns display a clear JavaScript error instead of failing silently, which makes experimentation and debugging easier. The plain-text match report can be copied into notes, tickets, documentation or test cases. This tool is useful for developers, QA testers, students, analysts and anyone preparing find-and-replace rules. All patterns and sample content stay on your device and are evaluated locally using the browser’s JavaScript RegExp engine. Toolexa does not upload or permanently store the expression or text. The responsive editor and preview are designed for both short checks and larger multi-line samples, with Clear available before beginning another test.
How to use Regex Tester?
- Enter a regular expression without slash delimiters.
- Select the flags required for the test.
- Paste or type sample text.
- Click Test Regex and inspect highlighted matches.
- Copy the report or clear the tester.
- Open the tool page and read the input labels carefully.
Regex Tester Features
- Enter JavaScript regular expressions
- Select common regex flags
- Highlight every match safely
- Show groups and match positions
- Load common regex examples
- Copy results and clear inputs
Regex Tester FAQs
Should I include slash delimiters?
No. Enter only the pattern; choose flags separately.
Which regex engine is used?
The tool uses the JavaScript RegExp engine provided by your browser.
Can it display capturing groups?
Yes. Captured group values appear in the match report.
Why can matches differ from another language?
Regular-expression syntax and features vary between JavaScript, PHP, Python and other engines.
Is sample text uploaded?
No. Testing and highlighting happen locally in your browser.