Regex Generator

A regex generator is a visual tool that helps you build a regular expression by combining building blocks — literals, character classes, quantifiers, anchors, and groups — instead of writing the pattern by hand. It assembles the correct syntax for you as you go.

A tester takes a pattern you already wrote and shows what it matches. A generator helps you build the pattern in the first place. You can use both together: build a pattern here, then paste it into our Regex Tester for deeper debugging.

No. Everything runs locally in your browser using the native JavaScript RegExp engine. Your patterns and test text never leave your device.

It produces ECMAScript (JavaScript) regular expressions. Most patterns also work in PCRE, Python's re, Java, Go, .NET, and Ruby, but advanced features may differ slightly.

Choose a Literal text block and type the character — the generator automatically escapes regex metacharacters (. * + ? ^ $ { } ( ) | [ ] \) for you so they match literally.

By default quantifiers are greedy — they match as much as possible. Lazy quantifiers (?, *?, +?, {n,}?) match as little as possible. Useful when extracting content between delimiters.

A character class [abc] matches any one of the listed characters. Use ranges like a-z, 0-9. A negated class [^abc] matches any character except those listed.

It's a non-capturing group — it groups alternatives or applies a quantifier to a sequence without creating a numbered capture. The generator uses non-capturing groups so output stays clean.

Yes. Use 'Pattern' to copy just the pattern body, or 'JS literal' to copy the full /pattern/flags form ready to paste into JavaScript or TypeScript.

Usually because of unbalanced brackets in a character class, an empty group, or an invalid quantifier range like {5,2}. The error appears under the generated pattern so you can spot the offending block immediately.