Why Your Browser Already Knows How to Parse Any URL Correctly

URLs have more structure than they look like

A URL looks like a simple string, but it's actually a precisely specified format with a protocol, an optional username/password, a hostname, an optional port, a path, a query string, and a hash fragment — each with its own rules about which characters are allowed and how they're escaped.

Why hand-written regex parsing breaks

A quick regex to "grab the domain from a URL" often works for typical cases but breaks on real-world edge cases: a port number, an internationalized domain name, unusual but valid character encoding in the query string, or a URL with no path at all. Each of these requires specific handling that a general-purpose regex usually doesn't account for.

The browser already solved this

Every browser ships a complete, spec-compliant URL parser as part of its JavaScript engine, exposed directly to web pages as the built-in URL object. Calling new URL(someString) gives you every component already correctly separated out, using the exact same parsing logic the browser itself uses to actually navigate — not an approximation of it.

Try it yourself

Our URL Parser uses exactly this built-in parser to break any URL down into its parts, including every query parameter, entirely in your browser.