How To Parse Urls

The URL API

The two-argument form resolves a relative URL against a base.

The eight components

Building URLs this way avoids every encoding mistake in the book. Manual string concatenation is where bugs live.

IDN domains and Punycode

The URL parser normalizes while it parses:

File URLs

Relative URLs and base resolution

URL vs URLSearchParams

Normalization

Data URLs and other schemes

Common mistakes

Run the numbers