Regex Tester
Test regular expressions in real time. Enter a pattern and test text to see matches instantly.
Testing Regular Expressions
A regular expression defines a search pattern, but the same pattern can behave differently depending on flags, escaping, and the text it runs against. This tester lets you type a pattern and sample text side by side, then highlights matches so you can see exactly what the expression captures.
How to Debug a Pattern
- Start with a small sample that contains a match and one that does not
- Check case sensitivity and multiline behavior
- Use a non-greedy quantifier when a match swallows too much text
- Escape special characters such as dots and parentheses when you mean them literally
Is my regular expression sent to a server?
No. Matching runs locally in your browser.