What is an MCP server?

An MCP server is a small program that exposes tools, resources, and prompts to AI agents using the Model Context Protocol — an open spec from Anthropic. Agents like Claude, ChatGPT, and Cursor use MCP to call external systems in a structured way without the user having to wire integrations one by one.

Is this a free alternative to the official MCP Inspector?

Yes. The official @modelcontextprotocol/inspector requires npx, Node, and a local proxy on localhost:6277. This inspector runs entirely in your browser — paste a URL and go. No install, no terminal, no Node version mismatch.

Do you store my server URL or my API tokens?

No. Everything stays in your browser. We do not proxy your requests, we do not log your URL, and we never see your Bearer tokens or custom headers.

My MCP server returned a CORS error — what do I do?

Add the Access-Control-Allow-Origin header for your domain. For quick local testing, run the official MCP inspector locally — it ships with a same-origin proxy that bypasses CORS entirely.

Can I share a link with the connection pre-filled?

Yes. After connecting, copy the page URL — it includes your server URL and transport choice as query parameters. Send the link to a teammate and they land on the same connected state.

Does this connect to my custom MCP server?

Today this explores popular public MCP servers so you can learn the shape of a server without any install. Live connection to your own server ships in v1.1 — join the waitlist in the CTA.

MCP Inspector Online — Test Any MCP Server in Your Browser

MCP Inspector Online is a free, browser-based inspector for the Model Context Protocol. Explore popular public MCP servers — browse their tools, resources, and prompts — without installing npx, Node, or a local proxy. No sign-up required.

What you can inspect

Tools — every callable tool the server exposes, with its full JSON Schema input definition and parameter list.
Resources — static and dynamic resources the server makes available to AI agents.
Prompts — prompt templates the server registers for agent use.

How it works

Pick a public MCP server from the quickstart row, or enter a server URL and transport (Streamable HTTP for modern servers, SSE for older ones). The inspector loads the server's spec in seconds and displays its full capability set — tools, resources, and prompts — in a structured, tabbed view. Click any tool to expand its JSON Schema and see the exact parameters it accepts.

Common questions

What is an MCP server?: An MCP server is a small program that exposes tools, resources, and prompts to AI agents using the Model Context Protocol — an open spec from Anthropic. Agents like Claude, ChatGPT, and Cursor use MCP to call external systems in a structured way.
Is this a free alternative to the official MCP Inspector?: Yes. The official @modelcontextprotocol/inspector requires npx, Node, and a local proxy on localhost:6277. This inspector runs entirely in your browser — no install, no terminal, no Node version mismatch.
Do you store my server URL or API tokens?: No. Everything stays in your browser. We do not proxy your requests, log your URL, or see your Bearer tokens or custom headers.
My MCP server returned a CORS error — what do I do?: Add the Access-Control-Allow-Origin header for your domain. For quick local testing, run the official MCP inspector locally — it ships with a same-origin proxy that bypasses CORS entirely.
Can I share a link with the connection pre-filled?: Yes. After connecting, copy the page URL — it includes your server URL and transport as query parameters. Send the link to a teammate and they land on the same connected state.
Does this connect to my custom MCP server?: Today this explores popular public MCP servers so you can learn the shape of a server without any install. Live connection to your own server ships in v1.1 — join the waitlist in the CTA.

Also need to test your site on mobile? Try the iPhone Simulator Online — render any URL inside accurate device frames with a live HUD overlay, free in your browser.