Regex Tester
Test regular expressions in real-time — highlight matches, inspect groups, replace and validate
Enter a regular expression and sample text to see matches highlighted as you type, inspect capture groups, test flags and try search-and-replace before using the pattern in your code. More free security tools.
Regular expressions are deceptively easy to get subtly wrong — a greedy quantifier that backtracks catastrophically, a capture group that shifts index when you add a new group earlier in the pattern, or a flag you forgot to set. This tester runs your pattern against the browser's native RegExp engine (the same engine your JavaScript code will use), so what you see here is what you'll get in production.
Matches highlight live as you type, capture groups are broken out individually so you can confirm you're referencing the right one, and the search-and-replace panel lets you test a substitution pattern — including backreferences — before you commit it to code.
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