.* Regex Tester
Test regular expressions against sample text and see matching results instantly.
Practical guide
How to use Regex Tester
Test regular expressions against sample text and see matching results instantly.
Common uses
- Debug regex patterns
- Extract matching text
- Test validation rules
- Learn regular expressions
Good practice
Start with small samples, test inputs that should and should not match, and watch for patterns that become extremely slow on long text. JavaScript regex syntax may differ from other languages.
Data handling
Test with synthetic data rather than production logs because logs often contain IP addresses, tokens, email addresses, or customer identifiers.
Frequently asked questions
What is regex?
A regular expression is a pattern used to match text.
Can I test multiple matches?
Yes. The tool lists matches found in your sample text.
Does regex syntax vary by language?
Yes. This browser-based tester uses JavaScript regular expression syntax.