The fastest way to discover, inspect, and test MCP servers — directly in your browser, with no local setup.
The MCP ecosystem is growing fast — hundreds of servers in the registry, more shipping every week. But there was no easy way to try them. Want to test a server? Install it locally, wire up stdio transport, write a client script, hope the schema is documented. Most developers gave up before seeing what a server actually does.
MCP Playground fixes that. Paste a URL, click connect, and you are interacting with the server in seconds. For npm stdio servers, the in-browser sandbox runs them without any local setup at all. Think of it as Postman for the MCP ecosystem.
Browse the Registry
Explore all publicly listed MCP servers. Filter, search, and see what tools each one exposes.
Connect & Inspect
Connect to any remote MCP server via Streamable HTTP, SSE, or WebSocket. View all tools, resources, and prompts with their schemas.
Test Tools Interactively
Auto-generated forms from JSON Schema. Fill in arguments, execute, see results — with full execution history.
Schema Linter
Grade any MCP server A–F with 15+ lint rules. Check tool descriptions, JSON Schema completeness, and token cost estimates.
Quality Dashboard
Registry-wide leaderboard grading every live MCP server A–F. Sortable table, grade distribution chart, and CSV export.
Public REST API
Programmatic access to inspect, lint, health-check, and browse the registry. CORS-enabled with rate limiting.
In-Browser Sandbox
Run any npm MCP server directly in your browser via WebContainers. No Node.js install, no terminal.
Traffic Inspector
See every JSON-RPC message between client and server. Debug protocol issues visually.
Share & Embed
Shareable links with auto-run. Embeddable iframes for docs. README badges for instant demos.
Auth Headers
Bring your own API keys and authorization headers. Session storage only — never sent to our servers.
All MCP connections happen server-side via a Next.js API route — your browser never talks to MCP servers directly. Auth headers stay in your browser's session storage and are forwarded securely. No data is stored on our servers.
The sandbox is the one exception: it runs the server process entirely in your browser via WebContainers (WASM), so nothing leaves your tab.
The Model Context Protocol is an open standard (created by Anthropic) for connecting AI models to external tools, data sources, and services. MCP servers expose three primitives:
MCP Playground is fully open source and MIT licensed. Contributions, feedback, and bug reports are welcome. If you are building an MCP server, we would love to help you get listed and tested.