What the number separates
9,178 pass when we test the behaviour. 4,121 do not.
Any directory can list sites that claim a standard — the claim is in the source and costs nothing. Separating the two requires testing the behaviour, and dating the result. That is the only thing on this page you cannot get elsewhere.
What Markdown negotiation is
A site that answers Accept: text/markdown with actual markdown hands an agent the content without the navigation, scripts and layout it would otherwise have to strip. The same URL, a cleaner representation. Read HTTP content negotiation (RFC 9110) — it is the authority on the design and we are not trying to be.
How we test it
We fetch the page twice — once as HTML, once with Accept: text/markdown — and compare. Since rubric v1.1 the check passes only when the body IS markdown AND differs from the HTML response.
A text/markdown content-type header on an HTML body was passing before v1.1. The header is a claim; the body is the evidence, and the two disagreed often enough to be worth re-probing the whole index for.
Sites that implement it
44.9% of these are on mintlify, 5.8% of these are on wordpress, 1.2% of these are on webflow. The platform supplies the machinery; the domain signals the commitment, and a report says which applies.
✓Business.Digital business.digitalExternal digital department for medium-sized companies in Germany, offering integrated web development, e-commerce, ERP, automation, AI, and software solutions with consulting and ongoing support since 2006.
shopware ✓David Bueno Vallejo davidbuenov.comSpanish professor and researcher David Bueno Vallejo offers technology consulting, AI training diagnostics, and publishes projects, blog posts, conferences, and educational resources on his personal website.
✓Delx delx.ai +1 more host on this domainDelx is an independent AI agent lab researching continuity, recovery, verifiable work, and governed exchange for autonomous systems, providing protocols, tools, and research artifacts for AI agent lifecycle and operational resilience.
✓EFROS efros.comUS cybersecurity-first MSP and MSSP offering managed IT, 24/7 SOC, system integration, and AI Governance for regulated industries including healthcare, financial services, manufacturing, logistics, and legal, serving nationwide from Chicago area.
✓Every every.toSubscription service offering AI-focused ideas, apps, training, and editorial columns from AI practitioners, including AI-powered software products and livestreamed camps, founded in 2020 and cited by major publications.
✓Faheem faheem-ai.appArabic AI-powered learning assistant aligned with the Egyptian curriculum, offering adaptive learning conversations, interactive tests with analytics, study booklets, and voice-first Q&A for Arabic-speaking students, parents, and educational institutions in Egypt.
✓JobsPipe jobspipe.devAPI platform providing live, deduplicated, normalized job postings from 30+ ATS and job boards, plus company technology stack scanning and labor market insights, serving global job data consumers and AI agents.
✓NVDC nvdc.aiDecentralized, verifiable, OpenAI-compatible GPU inference network with NVTrust attestation, offering paid GPU inference, attestation verification, USD payments via Stripe, and an experimental relay board for deferred jobs.
✓Cameron Rye Portfolio rye.devCameron Rye's personal portfolio and technical blog featuring software engineering projects, AI integration tools, MCP servers, and developer resources, with blog posts, project details, resume, and contact options accessible online.
✓VertoDigital vertodigital.comB2B digital marketing agency specializing in pipeline-driven marketing for technology companies with $10M–$500M ARR, offering inbound and outbound pipeline growth, pipeline intelligence, and a free Pipeline Readiness Assessment. Based in Sofia and Boston, serving US, UK, and EU clients.
✓a2b Logistics www.a2b.saB2B logistics company in Riyadh, Saudi Arabia offering trucking, warehousing support, customs-clearance coordination, supply-chain solutions, and fleet services with kingdom-wide coverage and 24/7 support.
✓Growth Academy Global www.growthacademy.globalGrowth Academy Global teaches established service business owners AI-era client acquisition via LinkedIn category ownership, LinkedIn Live, AI search visibility, and Codex agent workflows. Founded by Shanee Moret, it targets B2B owners selling $20K+ services.
The 9,530 listed sites that negotiate markdown or ship a markdown twin, through the API — a wider set than the one this page counts: every one, in a fixed order, 25 per call, with the total stated.
Own a site?
Markdown negotiation is one signal among several. The rubric says exactly what we look for and how each tier is reached, and a probe can be requested — the probe decides, never the request.
Method and date
Measured 2 Oct 2026. 57,273 listed as of 4 Nov 2026: 57,266 fetched twice in the full pass of 2 Oct 2026, and 7 probed since Every figure on this page carries the population it was measured against; a count without a denominator is not a measurement. How the index is built · All standards.