Regex Tester
Write a pattern, paste your test string — matches highlight instantly.
Flags:
Enter a pattern above
Quick Reference — click to insert
About Regular Expressions
Regular expressions (regex) are patterns used to match character combinations in strings. They're supported natively in JavaScript, Python, Go, Ruby, Java, and most other languages — though syntax details vary between engines. This tester uses the JavaScript RegExp engine.
Common gotchas: In JavaScript, the . character does not match newlines by default — use the s (dot-all) flag to change this. The ^ and $ anchors match start and end of the whole string by default — use the m (multiline) flag to make them match line boundaries instead.