Microsoft’s NLWeb Protocol: A Competitor to MCP?

At Build 2025, Microsoft unveiled NLWeb — a new initiative to standardize how natural language interactions happen across the web.

According to Microsoft, NLWeb aims to:

• Define how services expose capabilities in NL-friendly formats.
• Support agent-to-service interactions beyond simple APIs.
• Provide a more “conversational web.”

But how does NLWeb relate to the existing work of MCP (Model Context Protocol)?

What is NLWeb?

Microsoft’s vision for NLWeb includes:

• A schema for describing service capabilities and interaction flows.
• Support for .well-known/nlweb.json manifests.
• Guidelines for LLM-friendly interaction patterns.
• Built-in trust signals via signed manifests.

In short, it covers a similar space to MCP.

How does it compare to MCP?

Feature	MCP	NLWeb
Base standard	.well-known/mcp.llmfeed.json	.well-known/nlweb.json
Trust model	Signed feeds, certificate verification	Signed manifests (similar)
Capabilities	Explicit, extensible	Explicit, but Microsoft-curated
Governance	Independent (via wellknownmcp.org)	Microsoft-led
Community alignment	Cross-industry	Microsoft ecosystem-first

Risks of fragmentation

There is clear overlap between NLWeb and MCP. The risk is that:

• Sites may have to implement both.
• Agents may prioritize proprietary protocols.
• The ecosystem may fragment instead of converging.

Opportunities for convergence

There is also potential for:

• Interop between NLWeb and MCP.
• Mapping NLWeb schemas to MCP feeds.
• Joint work on trust and verification models.

The ideal outcome: NLWeb contributes to a richer MCP ecosystem — not a competing silo.

Our take

Microsoft’s engagement in this space is a sign that Agentic Web standards are gaining traction.

But:

• True openness and interoperability must remain priorities.
• The community must guard against ecosystem lock-in.

At wellknownmcp.org, we are already exploring mappings between MCP and NLWeb — and invite Microsoft to participate in these discussions.

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Next steps: We’ll track the NLWeb specification and advocate for alignment with MCP — so the Agentic Web remains truly open.

Stay tuned.