Comparison Guide 2026

MCP Playground: Test MCP Servers Without Setup

An MCP playground lets you test and debug MCP servers directly in your browser. Compare 7 MCP inspector tools including Smithery, Glama, MCP Inspector, and MCPize. Find the best tool for testing MCP tools online.

7 Tools Compared
MCP Debugging
No Setup Required
View ComparisonBrowse MCP Servers

Table of Contents

What is an MCP Playground?

An MCP playground (also called MCP inspector) is a debugging tool for testing Model Context Protocol servers. It provides a web or desktop interface to call tools, access resources, view prompts, and inspect JSON-RPC messages without writing code.

MCP server testing tools are essential for developers building or integrating MCP servers. They let you verify tool implementations, test resource access, and debug issues before deploying to production clients like Claude Desktop or Cursor.

Tool Testing
Call tools with form inputs
JSON-RPC Logs
View request/response
Resource Access
Browse and read resources
Live Debugging
Real-time error display

MCP Playground Comparison Table

Compare features across 7 MCP testing tools. Find the right playground for your debugging needs.

FeatureSmitheryMCPizeGlamaMCP InspectorMCP PlaygroundTRMXMCPJam
TypeWeb SaaSWeb SaaSWeb SaaSCLI + BrowserWeb SaaSDesktop AppWeb SaaS
LLM ChatFree + BYOKMulti-modelBuilt-inFree LLM
Free LLM?Grok 4.1 FastFreemiumGPT-4o/Claude
Multiple ServersParallel
Compare ModelsSplit-viewGPT vs Claude
Cost Tracking?
Sync Mode
Server Proxy
Tools List
Resources
Prompts
Form InputAuto-genAuto-genJSON Schema
JSON-RPC Logs
Export ConfigClaude/CursorClaude/Cursormcp.json
Agent TestsComingFuture
Hosted Servers2,800+500+44k+ tools
Free TierFreemiumOpen sourceOpen source

Key Differentiators: When to Use Which Tool

Smithery

Built-in hosting + Agent Unit Tests (coming)

MCPize Inspector
Recommended

Server-side proxy, split-view model comparison, cost tracking, 85% revenue share

Glama

Multi-model chat (GPT-4/Claude comparison), 44k tools

MCP Inspector

Official tool, export configs, local stdio support

MCP Playground

Zero-setup web testing, OAuth flows

TRMX

Desktop app, multiple parallel connections

MCPJam Inspector

Free GPT-4o/Claude/Gemini included, BYOK option

Last updated: December 2026. Data from official sources and testing.

Inspector Mode vs Chat Mode

Inspector Mode (No LLM)

Manually call tools and access resources. Full control over inputs. No LLM costs.

  • Direct tool invocation with form inputs
  • View raw JSON-RPC request/response
  • Zero token costs
  • Best for debugging and unit testing
Tools: MCP Inspector, scriptbyai, MCPize Inspector

Chat Mode (With LLM)

Natural language interaction. LLM decides which tools to call. Closer to production use.

  • ChatGPT-like conversation interface
  • LLM automatically selects tools
  • Tests real-world usage patterns
  • Requires API key or paid tier
Tools: Glama, Smithery, TRMX, MCPize (BYOK)

BYOK: Best of Both Worlds

Bring Your Own Key (BYOK) lets you use Chat mode with your own OpenAI/Anthropic API key. You control costs and the platform charges no LLM markup. MCPize uses this approach for Chat mode while keeping Inspector mode completely free.

Who Pays for LLM Tokens in Chat Playgrounds?

Chat mode requires an LLM. Different platforms handle token costs differently.

PlatformPayment ModelDetails
Glama
BYOK + Paid plan
Free tier = basic chat. Paid ($26/mo) = MCP + more models. Need API key via "Gateway"
MCPJam
Free + BYOK
Free GPT-4o, Claude Sonnet, Gemini 2.5 included. Or use your own key
Smithery
Unclear
Playground available, but pricing not public. Requires Smithery API key
MCP Inspector
No LLM
Manual testing only, no chat feature. Zero token costs
MCPize
BYOK Only
Inspector = free, no LLM. Chat = your API key, no markup. You control costs

LLM Chat Business Models Explained

BYOK (Bring Your Own Key)

  • User provides OpenAI/Anthropic API key
  • Platform proxies requests
  • User pays LLM provider directly
  • Platform: $0 LLM cost

Platform Pays (Loss Leader)

  • Platform provides free LLM access
  • Attracts users, builds ecosystem
  • Monetizes later (hosting, enterprise)
  • MCPJam model: free GPT-4o/Claude

Subscription Includes LLM

  • Monthly fee ($26/mo Glama)
  • Includes X tokens/month
  • Overage billed separately
  • Predictable revenue for platform

Per-Token Billing

  • User pays per request
  • Platform adds margin on top
  • Transparent, pay-as-you-go
  • Fair for light usage

MCPize Approach: Transparent BYOK

MCPize Inspector is 100% free with no LLM costs. For Chat mode, we use BYOK only — you provide your API key, pay your LLM provider directly, and we add zero markup. No hidden fees, no subscriptions required for testing.

Key MCP Playground Features

Tool Testing

Call MCP tools with auto-generated forms from JSON Schema. View results instantly without writing code.

JSON-RPC Logging

Inspect raw request/response payloads. Essential for debugging schema issues and error handling.

Resource Browser

List and read MCP resources. Verify URI patterns and content types work correctly.

Prompt Testing

View available prompts and test them with different arguments. Essential for prompt-heavy servers.

SSE/HTTP Support

Connect to remote servers via SSE or HTTP transport. Test hosted deployments directly.

OAuth Integration

Test servers that require authentication. Handle OAuth flows without manual token management.

Coming Soon

MCPize Inspector & BYOK Chat

A two-phase approach to MCP testing: free Inspector mode for debugging, BYOK Chat for production testing.

Phase 1

Inspector Mode

Test your deployed MCP servers without any LLM costs.

  • Call tools with form-based inputs
  • View resources and prompts
  • JSON-RPC request/response logs
  • Test different server revisions
  • 100% free, no API key required
Phase 2

BYOK Chat Mode

Add your API key for natural language MCP testing.

  • ChatGPT-like interface
  • LLM automatically calls tools
  • Support for OpenAI, Anthropic, others
  • Test production usage patterns
  • Your key, your costs, no markup

What Makes MCPize Inspector Different

Revision Testing
Test specific deployment versions
Deployment Integration
Test before promoting to production
OAuth Testing
Built-in auth flow support

How to Test MCP Servers Online

1

Choose a Playground

Pick based on your needs: MCP Inspector for local debugging, Smithery/Glama for hosted servers, MCPize for deployment integration.

2

Connect to Your Server

Enter the server URL (for remote) or start via CLI (for local). Most playgrounds support SSE and HTTP transports.

3

Test Tools and Resources

Use the generated forms to call tools with different inputs. Check resources and prompts work correctly.

4

Debug with JSON-RPC Logs

Inspect raw request/response payloads to identify schema issues or error handling problems.

Frequently Asked Questions

Which MCP Playground Should You Use?

Choose based on your primary use case:

Local Debugging

MCP Inspector

Official tool from Anthropic. Best for local development with stdio transport.

View on GitHub
Free Hosting

Smithery

Free hosting with built-in playground. Great for quick testing of deployed servers.

Compare Smithery
Enterprise

Glama

AI workspace with VM isolation. Best for enterprise security requirements.

Compare Glama
Monetization + Testing

MCPize

Deploy, test, and monetize. Inspector for debugging, BYOK Chat for production testing.

Start Building
Desktop App

TRMX

Cross-platform desktop client. Supports multiple server connections in parallel.

Visit TRMX
Zero Setup

MCP Playground

Quick web testing at scriptbyai.com. No account needed for basic functionality.

Try It

Explore All MCP Platforms

All ComparisonsSmitheryGlamamcp.soBrowse MCP Servers
Build & Monetize

Ready to Build Your Own MCP Server?

Deploy your MCP server on MCPize. Get hosting, testing tools, and 85% revenue share.

Start BuildingBrowse Marketplace