WebFinger validator

Per RFC 7033

Queries /.well-known/webfinger for a resource and checks JRD structure, content type, subject and link structures.

What is this, and when do I need it?

What is this?

WebFinger (RFC 7033) discovers information about people or services from an account identifier (acct:user@host) or URL. The host serves a JRD (JSON Resource Descriptor) document at /.well-known/webfinger?resource=... that lists aliases, properties and links to profile pages or protocol endpoints (ActivityPub, Matrix, OpenID Connect issuer). This tool fetches and validates the JRD against the spec: content type application/jrd+json, required subject, link structures, rel values.

When do I need it?

Setting up Fediverse identity discovery, debugging a Matrix homeserver delegation, or verifying that an external partner publishes a usable WebFinger endpoint before you wire clients against it.

Sensible next steps

Server path: this tool does NOT run browser-local. We fetch the JRD via our server (browsers cannot do CORS-free fetches against foreign .well-known paths). We do not log the resource or the result. 12 requests per minute per IP.