WebMCP vs MCP

WebMCP tools live on your web page and run in the visitor's browser, so an agent that is browsing your site can call them while it is there. MCP is a server protocol that connects apps such as ChatGPT or Claude directly to a service. Most websites start with WebMCP for agents that visit, and add an MCP server when customers want a direct connector.

The difference at a glance

	WebMCP	MCP
Where the tool runs	In the browser, on your web page	On a server you operate
Who calls it	An agent browsing your site	An AI app the user has connected
Sign-in	Uses the visitor's existing page session, if any	Usually OAuth or an API key
How it is found	Registered by the page at runtime	Configured in the AI app, or a server card
Typical setup	A script or form attributes	A hosted MCP server
Status	W3C Community Group draft, testable in Chrome	Published open protocol

Chrome's own comparison puts it simply: MCP connects an AI platform to your service, while WebMCP lets your page act as the tool provider for an agent that is already there.

When should a website use WebMCP?

Use WebMCP when agents reach your site through a browser and need to find answers or take the next step: a hotel guest asking about parking, a shopper comparing products, a buyer looking for the right contact. The tools sit next to your existing pages, so nothing has to be rebuilt.

LightSite's WebMCP setup adds four read-only tools of this kind and tracks every call and question.

When do you need an MCP server?

You need MCP when users want to work with your service from inside ChatGPT, Claude or another AI app without opening your website: querying their account data, running reports or triggering actions they are signed in for. LightSite's own MCP connector works this way, letting customers analyse their AI search data inside ChatGPT and Claude.

Can you use both?

Yes, and they do not conflict. WebMCP serves agents on your public site; MCP serves signed-in users inside AI apps. The agent readiness checker looks for both: WebMCP signals in your page and an MCP server card in /.well-known.

How to measure what agents do with each

For an MCP server you measure calls on your own server. For WebMCP the calls happen in the visitor's browser, so you need tracking on the page. LightSite records each WebMCP tool call with the question asked, whether it was answered and what the agent did next on your site.

Frequently asked questions

Is WebMCP the same as MCP?

No. They share ideas, such as named tools with input schemas, but WebMCP runs in the browser on your page and MCP runs on a server.

Which should I set up first?

For a public marketing, hotel or ecommerce site, WebMCP usually comes first because it serves agents that already visit.

Does LightSite support both?

LightSite installs read-only WebMCP tools on your site and offers its own MCP connector for analysing your AI search data in ChatGPT and Claude.

Sources

Last updated 2026-11-06