Test regular expressions live — matches, capture groups and replace, all in your browser.
The Regex Tester lets you build and test regular expressions against sample text with live match highlighting, so you can perfect a pattern before dropping it into your code.
It's an essential companion for developers wrangling search, validation, and text-processing patterns.
The tester compiles your pattern with the flags you set and runs it against the sample, highlighting every match and capture group as you type. Instant feedback turns the usual trial-and-error of regex into a tight, visual loop.
Because it runs in your browser, you can test patterns against sensitive sample data without it leaving your device.
Write a pattern for email-like strings, paste a paragraph, and watch the matches light up — letting you catch a false positive and tighten the pattern before it ships.
JavaScript's regular-expression engine, matching what runs in browsers and Node.
Yes — matches and groups are highlighted as you type.
No — testing happens entirely in your browser.
Yes — set the flags and see their effect live.
Yes — 25 languages, free to use.