Regex Parser
The parser behind regex101, now available as a commercial npm package for your own product.
If your app depends on regex features, this package gives you the hardest part out of the box: full flavor coverage, fast parsing, and engine-accurate validation you can rely on in production.
Why teams choose it
- Build faster: skip years of parser edge cases and maintenance work.
- Stay accurate: validation follows official engine behavior, not a simplified grammar.
- Keep editing fast: designed for real-time parsing on every keystroke.
- Integrate quickly: simple API, fully typed, works in browser and Node.js.
Proven in production
- Used by millions of regex101 users.
- Backed by 2000+ tests and 97% code coverage.
- Parses the RFC822 email regex in under 10ms on a modern MacBook Pro.
What makes it different
It combines speed and correctness in one parser. Dynamic references are resolved in real time, including advanced cases like variable-width lookbehind validation.
A good fit for
- IDE and editor tooling
- SaaS products with regex features
- Security and analysis platforms
- Internal developer tools
- Open source maintainers who want commercial-grade reliability
Start here
For licensing and package access, contact contact@regex101.com. We are happy to help you choose the right plan.