#url

Expand URI Templates (RFC 6570) — the standard used by GitHub, OpenAPI/Swagger, HAL and many hypermedia APIs — to build URLs from a template and a set of variables. The expand endpoint takes a template such as /users/{user}{?page,per_page} and a JSON object of variables, and returns the finished URI with everything correctly percent-encoded. It implements all four levels of the spec: simple expansion {var}; reserved {+var} and fragment {#var} expansion; the label {.var}, path {/var}, path-style-parameter {;var}, query {?var} and query-continuation {&var} operators; multiple variables {x,y}; and the value modifiers — prefix {var:3} (first N characters) and explode {var*} (expand lists and maps element by element). Variables can be strings, lists or associative maps. The parse endpoint inspects a template and lists its expressions, operators and variable names. Everything is computed locally and deterministically, so it is instant and private. Ideal for REST and hypermedia clients, API SDKs and code generators, OpenAPI tooling, and link building. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This expands URI templates; for building or parsing query strings use a query-string API and for canonicalising URLs use a URL API.

api.oanor.com/uritemplate-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

Parse and build URL query strings — with full support for nested objects and arrays. Turn a query string like a[b][c]=1&tags[]=x&tags[]=y into a clean nested JSON object, and turn any JSON object back into a properly-encoded query string. Choose how arrays are serialised (indices, brackets, repeated keys or comma-separated) and whether to URL-encode. Far beyond a flat key=value encoder — it handles the deep structures real web frameworks (Rails, PHP, Express/qs) use. Pure local processing — no key, no third-party service, instant. Live. 3 endpoints. Built for API request construction, parsing complex links and redirects, form-encoded bodies and webhook payloads.

api.oanor.com/querystring-api

The IANA Uniform Resource Identifier (URI) Schemes registry as an API — all 413 registered schemes (http, https, mailto, tel, ftp, ssh, magnet, bitcoin, geo, did, …). Look up any scheme to get its description, registration status (Permanent, Provisional or Historical) and defining reference; search by name or description; or list all schemes filtered by status. Ideal for URL parsers and validators, link handlers, deep-linking, security allow-lists and developer tooling that needs to recognise or vet URI schemes.

api.oanor.com/urischemes-api

Parse any hostname or URL with the Public Suffix List. Split a domain into its subdomain, registrable domain (eTLD+1) and public suffix (eTLD), or fetch just the suffix or just the registrable domain. Handles full URLs, internationalized (punycode) domains, IP addresses, multi-level suffixes like co.uk and com.au, and — when you ask for it — private suffixes such as github.io and s3 buckets. Built on an always-current Public Suffix List and served entirely in-memory, so responses are instant and the service is always available. Ideal for cookie and domain scoping, analytics attribution, email and link validation, security and anti-abuse, and devops tooling.

api.oanor.com/domain-api

Unfurl link previews — title, description, image, site name and favicon (Open Graph + meta tags) — and expand / unshorten URLs by following redirects to their final destination. Perfect for chat unfurls, link cards and resolving short links.

api.oanor.com/url-api