Regex Tester
Test regular expressions with flags and inspect all matches with capture groups.
Enter a pattern and text.
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Overview
Test regular expressions with sample text and flags. Useful for validation rules, log parsing, and extraction checks.
How to use
- Enter pattern and test text.
- Set flags such as g/i/m.
- Run and inspect matches and groups.
Examples
-
Email-like match
Input: Pattern: \w+@\w+\.\w+
Output: Finds simple email-like strings.
-
Line start
Input: Pattern: ^ERROR (m flag)
Output: Matches ERROR at each line start.
Notes
- Some engines differ in regex syntax.
- Overly broad patterns can cause slow performance.
- Escape backslashes correctly.
FAQ
- Why no match found?
- Check anchors, flags, and escaping first.
- What does g flag do?
- It searches all matches, not just the first.
- Can regex freeze input?
- Complex backtracking patterns can be expensive.
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