Regex Tester
Test a regular expression against a string and see the matches.
Worth Knowing
This runs your pattern through the browser's native JavaScript RegExp engine, so anything that works here will behave identically in real JS code — no simplified or separate regex dialect. One behavior worth knowing before you rely on a pattern: quantifiers like + and * are greedy by default, matching as much text as possible while still letting the overall pattern succeed. A pattern like <.+> against "<b>bold</b>" will match the entire string rather than stopping at the first closing tag, unless you add a ? after the quantifier to make it lazy instead.
How to Use
- Paste or type your pattern into the Regex Tester above.
- Set any additional options: Flags, Test string.
- The output updates instantly and is ready to copy.