Web
Regex Tester
Test JavaScript regular expressions live. Highlights matches, capture groups and quantifiers in real time.
Groups
- #1 ada@example.com→ ["ada", "example.com"]
- #2 grace@navy.mil→ ["grace", "navy.mil"]
Why use our Regex Tester?
100% private
Everything runs in your browser. Your data never leaves your device — safe for production payloads.
Instant results
No round trips, no rate limits, no login. Format, validate and inspect megabytes of JSON in milliseconds.
Standards-first
Follows RFC 8259 / ECMA-404 exactly. Reports errors with precise line and column diagnostics.
Related developer tools
CSS Formatter
Format and beautify CSS or SCSS with consistent whitespace, property ordering and rule indentation.
OpenGraphQL Formatter
Pretty-print GraphQL queries and schemas with consistent indentation. Handy for readable queries in code review.
OpenHTML Formatter
Beautify HTML with consistent indentation, wrap long attributes and preserve inline scripts. Powered by js-beautify.
OpenHTML Viewer
Preview HTML markup in a sandboxed live iframe. Toggle raw and rendered views without leaving your browser.
OpenJavaScript Beautifier
Beautify minified JavaScript, TypeScript or JSX with configurable indentation. Powered by js-beautify.
OpenMarkdown Formatter
Clean up Markdown — normalize blank lines, trim trailing whitespace, spacing around headings.
Open