Regex Testing Tool – Test regular expressions in real-time
The regex testing tool allows you to test regular expressions in real-time. Enter a regex pattern and test text to see matches highlighted immediately.
The tool shows matches, capture groups, and replacements. Supports JavaScript regex syntax with flags (g, i, m, s). Perfect for developers, data processing, and text searching.
How to get started with regex?
Start with basic notations: `.` means any character, `*` zero or more repetitions, `+` one or more, `?` zero or one. `\d` is a digit, `\w` is a word character, `\s` is whitespace. Parentheses `(abc)` create a capture group. For example, email regex: `[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}`. The regex testing tool helps you experiment and learn.
Loading tool...
Not sure what to try next?
Browse all tools →Regex testing tool helps write, test, and debug regular expressions in real-time. An invaluable tool for developers working with text data and pattern matching.
Write a regex pattern and test text, and the tool shows matches in real-time.
- Test regex patterns and see matches highlighted in real-time.
- View capture groups broken down separately.
- Try different flags: global, case-insensitive, multiline.
Highlighted matches show where the text matches your regex – check if the result matches your expectations.
- Too broad regex matches everything – too strict matches nothing. Test edge cases.
- Capture groups tell you which parts of the match are saved for use.
- Regex syntax may vary slightly between programming languages.
Regex is powerful but hard to read – comment and document complex expressions.
- Catastrophic backtracking can make regex very slow – avoid nested repeating groups.
- Always test regex with multiple inputs, including empty and special character strings.
- Tool runs in browser – your text data is not sent anywhere.