Regex Tester
/ /
Test string
0
Quick reference & common patterns
\d digit
\w word char
\s whitespace
. any char
^ start
$ end
* 0+
+ 1+
? 0 or 1
{n,m} n–m times
[abc] set
[^abc] not set
(…) group
(?<n>…) named
a|b or
\b word boundary
\B non-boundary
(?=…) lookahead

Free Regex Tester — test JavaScript regular expressions, live, no signup

Write a regular expression and see exactly what it matches in your text, highlighted as you type. Inspect every capture group, toggle flags, and start from common patterns. It uses the JavaScript (ECMAScript) engine and runs entirely in your browser — no signup, nothing uploaded.

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Everything runs in your browser

Matching uses your browser's built-in RegExp engine — the same one in Node.js and every modern browser. Your pattern and your test text never leave the page, so you can safely test against real data.

What you can do

Frequently asked questions

Do I need to sign up or install anything?

No. There is no signup and nothing to install. The regex tester runs entirely in your browser — type a pattern and your text and see matches highlighted instantly.

Which regex flavor does it use?

JavaScript (ECMAScript) regular expressions, the same engine your browser and Node.js use. All standard flags are supported: g, i, m, s, u and y.

Is my text sent to a server?

No. Matching happens locally in your browser using the built-in RegExp engine. Nothing you type is uploaded anywhere.

Can I see capture groups?

Yes. Each match lists its position and every capture group, including named groups, so you can debug complex patterns.

Can I replace or substitute text with a regex?

Yes. Switch the matches panel to the Replace tab, type a replacement string and see the substituted text update live. You can reference capture groups with $1, $2, named groups with $<name>, and the whole match with $& — then copy the result.