Regex Tester

Test and debug regular expressions online with live pattern matching.

Regex Pattern

Flags

Test String

About Regex Tester

Regular expressions (regex) are patterns used to match character combinations in strings. Our free online Regex Tester helps developers quickly build, validate, and test regular expressions in real-time.

Frequently Asked Questions

What do common Regex flags mean?

The "g" flag stands for global search (find all matches), "i" for case-insensitive search, and "m" for multi-line search.

Is my input string processed on a server?

No, all regular expression evaluations run client-side in your browser using standard JavaScript RegExp engines.