URL Canonicalize API
Normalize URLs to a canonical form so you can deduplicate, compare and clean them. The canonicalize endpoint lower-cases the scheme and host, drops the default port (80 for http, 443 for https), resolves ./ and ../ path segments and fixes percent-encoding using the standard WHATWG URL parser, then applies the cleanups you choose: strip marketing and analytics tracking parameters (all utm_* plus gclid, fbclid, msclkid, yclid, mc_eid and many more), sort the remaining query parameters into a stable order, optionally drop the #fragment, and add or remove the trailing slash. It returns the canonical URL, the fully parsed components and the exact list of changes it made. The compare endpoint canonicalizes two URLs and tells you whether they point to the same resource — perfect for catching duplicate links that differ only by tracking codes, casing, port or parameter order. Everything is computed locally with no network calls, so it is instant, private and safe. Ideal for crawlers and SEO tooling, link deduplication and analytics, cache keys, bookmarking and content pipelines. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This canonicalizes the URL string; it does not fetch it or follow redirects — for link previews and unshortening use a URL-unfurl API.
api.oanor.com/urlcanon-api
