Markdown Alternate Checker

Find out whether a page advertises a Markdown version of itself to AI agents.

Looks for a Markdown alternate declared with a <link rel="alternate" type="text/markdown"> element or an equivalent HTTP Link header, and checks that the advertised file actually resolves. A missing alternate is informational: most sites never publish one.

This is one of the checks the AI Agent Readiness Checker scores under Content, and it can also be run on its own for any URL.

Experimental · Based on: RFC 8288 — Web Linking · WHATWG HTML Living Standard

About this validation

Experimental / emerging convention

Looks for a Markdown alternate advertised through a link relation, either as an HTML <link rel="alternate"> element or an HTTP Link header. Web Linking is a ratified standard; using it to advertise a Markdown copy of a page is an emerging convention.

Protocol / standard:: RFC 8288 — Web Linking
WHATWG HTML Living Standard
Rules reviewed:: Nov 11, 2026

Standards and vendor-documented behavior can change. This reflects the source as last reviewed above, not a permanent guarantee.