Regular Expression Tester
Validate, test, and debug your regular expressions in real-time. No data ever leaves your browser.
Explanation
([a-zA-Z0-9._%+-]+)
1st Capturing Group. Matches any alphanumeric character, dots, underscores, percents, pluses, or hyphens.
@
Matches the literal character @.
([a-zA-Z0-9._%+-]+)
2nd Capturing Group. Matches domain name patterns followed by a dot and a TLD of at least 2 characters.
Matches
0Quick Reference Guide
anchor Anchors
- ^ Start of string
- $ End of string
- \b Word boundary
category Character Classes
- \d Digit [0-9]
- \w Word [a-zA-Z_0-9]
- \s Whitespace
repeat Quantifiers
- * 0 or more
- + 1 or more
- ? 0 or 1
Frequently Asked Questions
Which regex flavor does this tester use?
JavaScript's native RegExp engine (ECMAScript), the same one used in Node.js and browsers. Most patterns are compatible with PCRE, but some advanced features differ.
What do the common flags mean?
g finds all matches instead of the first, i makes matching case-insensitive, m makes ^ and $ match at line breaks, and s lets the dot match newline characters.
Is my test text sent to a server?
No. Pattern matching runs live in your browser using JavaScript's built-in regex engine — nothing is uploaded.