Regex Tester
Test regular expressions with live match highlighting
π 100% client-side β your data never leaves this page.any char\ddigit\wword char\swhitespace^start$end*0 or more+1 or more?0 or 1{n}exactly n[abc]char class(x)groupAbout this tool
Write a regular expression and test it against any string. All matches are listed with their index position and capture groups. Supports all JavaScript regex flags (g, i, m, s). Includes a quick reference card for common patterns. Everything runs in your browser with zero latency.
Frequently Asked Questions
Which regex flavor is used?
This tool uses JavaScript regular expressions (the built-in RegExp engine), which supports most common regex syntax including lookahead, named groups, and Unicode.
What do the flags mean?
g (global) finds all matches. i (case insensitive) ignores case. m (multiline) makes ^ and $ match line boundaries. s (dotAll) makes . match newlines too.
How do I use capture groups?
Wrap part of your pattern in parentheses: (\w+). Each group appears separately in the match results, making it easy to extract specific parts of a match.