# WebMCP: how many sites actually implement it Home > Standards > WebMCP **580 of 647 tested sites implement WebMCP.** Measured 2026-08-31. full-index static pass 30 Aug 2026 · 14,351 listed · 11,538 hosts asked · 1,224 could not be asked · 647 carrying the code · runtime-tested 31 Aug 2026 Checks passed across the 580 probed hosts: Markdown negotiation 375 · Markdown twin at a predictable URL 102 · llms.txt 377 · API catalog 542 · MCP server card answers 92. 67 carry it without it working. Any directory can list sites that claim a standard; separating the claim from the behaviour is what this measurement is. Check a site for WebMCP: https://knowngood.sh/verify/webmcp — free, anonymous, and it has no effect on any ranking or listing. ## What it is WebMCP lets a page register tools an agent can call, in the page itself, rather than at a separate endpoint. The site declares what can be done and the agent calls it directly — the page becomes the API. Specification: https://github.com/webmachinelearning/webmcp ## How we test it We execute the page in a headless browser with a modelContext supplied, exactly as an agent browser would, and count what it registers. Tools are ENUMERATED and never called: invoking a stranger's tool could place an order. A static scan of the source proves a registration EXISTS. It does not prove anything registers. A script that throws, is gated behind consent, or never runs registers nothing — and the first version of our own harness got this wrong in the opposite direction, scoring pages that shipped their own modelContext polyfill while missing conformant implementations that wait for the browser to supply one. The rate replicates: 89.6% on 31 August against 89.9% on the 30th, five days apart and on an independently re-derived host list. ## Sites that implement it - [Ben Milne](https://knowngood.sh/site/benmilne.com.md): Personal blog by Ben Milne featuring essays on value design, protocol thinking, and stablecoin topics. - [Business.Digital](https://knowngood.sh/site/business.digital.md): Business.Digital is a digital agency offering consulting and implementation for websites, shops, ERP, AI, and software since 2006. - [CostLoop](https://knowngood.sh/site/costloop.app.md): CostLoop is a SaaS tool for freelancers, startups, and SMBs to track software subscriptions, renewal dates, costs, and detect savings opportunities. - [Cyberkov](https://knowngood.sh/site/cyberkov.com.md): Cyberkov is a cybersecurity and signal security company in Kuwait offering penetration testing, TSCM, MDR, SOC, digital forensics, and counter-espionage services. - [Elektro Hübner](https://knowngood.sh/site/elektro-huebner-gmbh.de.md): Elektro Hübner provides electrical installation and maintenance services including photovoltaic, wallbox, and e-check in the Rhein-Main region. - [JobsPipe](https://knowngood.sh/site/jobspipe.dev.md): JobsPipe provides a unified API aggregating job postings from Workday, Indeed, Glassdoor, and 30+ ATS sources with normalized JSON and a free tier. - [NVDC](https://knowngood.sh/site/nvdc.ai.md): NVDC is a decentralized, OpenAI-compatible GPU inference network with NVTrust attestation and USD settlement via dual-signed receipts. - [Cameron Rye](https://knowngood.sh/site/rye.dev.md): Portfolio of Cameron Rye, a software engineer connecting legacy protocols to modern AI with open-source MCP servers and 20+ years experience. - [SpeakSafely](https://knowngood.sh/site/speaksafely.com.md): Brazilian SaaS platform providing anonymous corporate whistleblowing channels compliant with NR-01 and Lei 14.457, integrating WhatsApp and web for risk management. - [The Glocal Partners](https://knowngood.sh/site/www.theglocalpartners.com.md): The Glocal Partners provides management consulting services focused on GCC leaders with expertise in leadership coaching, customer experience, and talent development. - [Capturing Brand Emotions by UTC!](https://knowngood.sh/site/www.utc.de.md): UTC! GmbH is a live marketing agency specializing in innovative photo and video systems for events, offering purchase, long-term rental, and full-service solutions. - [Aboniki.es](https://knowngood.sh/site/aboniki.es.md): Aboniki Balm is a natural topical balm from Nigeria for muscle and joint pain relief, sold mainly via Amazon Spain and Afro-Caribbean stores. - [Clément Deust](https://knowngood.sh/site/ai-architect.tools.md): AI Architect provides verification-first Claude Code consulting with traceable, deterministic AI agent activations and audits. - [AiToolsObserver](https://knowngood.sh/site/aitoolsobserver.com.md): AiToolsObserver provides discovery, insights, trends, comparisons, and real-world use cases for AI tools and products. - [402pixels](https://knowngood.sh/site/api.402pixels.com.md): 402pixels offers an API for buying and reading 5x5 pixel blocks on a 500x500 grid using USDC on Base network. - [Apparel Monster](https://knowngood.sh/site/apparel.monster.md): Apparel Monster is an online retailer selling men's, women's, and sportswear clothing with 116 products across 30 categories priced in USD. - [Aptos Documentation](https://knowngood.sh/site/aptos.dev.md): Aptos Developer Documentation provides guides, SDKs, and tools to build Web3 applications on the Aptos blockchain. - [Aptos Documentation](https://knowngood.sh/site/aptos.guide.md): Aptos Documentation provides developer guides, SDKs, tools, and APIs to build Web3 applications on the Aptos blockchain. - [Beauty Leaders](https://knowngood.sh/site/beauty-leaders.com.md): Beauty Leaders offers online masterclasses teaching make-up techniques from industry professionals. - [BRITECITY](https://knowngood.sh/site/britecity.com.md): BRITECITY is a managed IT services provider in Irvine, California serving over 150 businesses in Orange County since 2007. - [CareFromChina](https://knowngood.sh/site/carefromchina.com.md): Care From China offers sourcing, supplier vetting, quality control, and logistics services for importing products from China. - [Cattive](https://knowngood.sh/site/cattive.com.md): Cattive is an AI-first platform for regional news portals in Brazil offering editorial technology, multi-tenant management, monetization, and distribution tools. - [Hugues Clouâtre](https://knowngood.sh/site/clouatre.ca.md): Technology executive Hugues Clouâtre shares AI and platform engineering insights and practical guides for CTOs and engineering leaders. - [dnsbin.ca](https://knowngood.sh/site/dnsbin.ca.md): dnsbin.ca provides DNS inspection tools including lookup, propagation checks, DNSSEC validation, RDAP, reverse DNS, mail health, discovery, and shareable snapshots. - [伴走型DX支援サービス｜株式会社ユルリカ](https://knowngood.sh/site/dx.yurulica.com.md): 伴走型DX支援サービス offers monthly subscription-based DX strategy, system development, AI utilization, and operational support for mid-sized and small enterprises in Japan. ## Through the API [All 580 of these sites, through the API](https://knowngood.sh/api/find?has_webmcp=true&limit=25): every one, in a fixed order, 25 per call, with the total stated. ## Method Measured 2026-08-31. Every figure carries the population it was measured against. Rubric: https://knowngood.sh/benchmark