Regex Tester
Test, debug, and inspect regular expression matches interactively.
Matches
No matches found.
About Regex Tester Online
Test and debug regular expressions with live match highlighting, group capture display, and flags support. Free, fast, no signup. This page is part of UtilsNest's Developer Tools, so you can move between related workflows without leaving the browser.
How to use it
- Enter or adjust the values, text, or file input needed for Regex Tester Online.
- Review the generated result instantly and compare outputs until the result fits your use case.
- Copy, download, or continue to a related developer tools workflow if you need the next step.
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Open Developer ToolsFrequently Asked Questions
What regex flavors does this tool support?
This tool uses JavaScript regex (ECMAScript flavor), which covers most real-world use cases including lookahead and Unicode support.
What are regex flags?
Flags modify matching behavior. "g" (global) finds all matches, "i" (case-insensitive) ignores case, "m" (multiline) matches across newlines.