Regex-testeri

The regex tester lets you build and debug regular expressions against your own sample text, with matches highlighted live as you type. It is useful for validating input formats, extracting fields from logs, or testing a pattern before pasting it into code.

Everything runs in your browser, so your patterns and test text are never uploaded.

It uses the JavaScript regular-expression engine, the same one in every browser and in Node.js, so a pattern that works here works in your JavaScript and TypeScript code.

Toggle the global, case-insensitive, multiline and other flags to change how a pattern matches. You see every match along with its capture groups, so you can confirm exactly what each part of the pattern is pulling out.

Other languages such as PCRE, Python and Go share most syntax but differ in some features, so a few advanced constructs may behave differently outside JavaScript. If a pattern works here but not in another language, an engine-specific construct is usually the reason.