Regex Builder & Tester
Templates + options + live matching to craft solid regular expressions.
[abc]Any of a, b, or c[^abc]Not a, b, or c[a-g]Character between a & g.Any character (except newline)\wWord character\dDigit\sWhitespaceconst regex = //gu; const str = 'test string'; const matches = str.match(regex); console.log(matches);
What is Regex Generator
Start from a template or write the pattern yourself: common-match templates seed the expression, flag toggles (g, i, m) sit beside it, and your pasted test text highlights matches as you type — a replacement field previews substitutions and syntax errors surface immediately with a message.
How to use Regex Generator
- Pick a template or type the pattern
- Toggle flags like global, case-insensitive, multiline
- Paste test text to see highlighted matches and the replace preview
- Copy the working regex
Frequently asked questions
Which regex flavor is used?
JavaScript (ECMAScript) syntax — close enough for most engines, though lookbehind and named-group support varies by language.
Can I preview replacements?
Yes — fill the replace field and the tool applies the substitution live, so you can verify capture-group references like $1 before copying.
Will my pattern work in Python or Java?
Core syntax (quantifiers, groups, classes) carries over, but flags and advanced features differ; always re-test in the target engine before shipping.
Is Regex Generator free?
Regex Generator is completely free — open the page and use every feature with no hidden charges.
Do I need to download or install Regex Generator?
No download or installation is needed. It is an online tool that runs in the browser on your phone, tablet and computer.
Do I need an account to use Regex Generator?
Yes — you need to sign in so your usage history and data can be saved. Sign-up takes a minute.
Does Regex Generator work on mobile?
Yes. The page is fully responsive and works on phones, tablets and desktop browsers.