What is the key difference between Firefox Devtools MCP and Zen MCP?

Firefox Devtools MCP belongs to the Browser Automation category with local stdio execution, while Zen MCP belongs to the Browser Automation category with local stdio execution.

How do I install Firefox Devtools MCP or Zen MCP in Claude Desktop or Cursor?

Copy the mcpServers JSON configuration snippet provided on this page into your claude_desktop_config.json or ~/.cursor/mcp.json file and restart your AI client.

Are Firefox Devtools MCP and Zen MCP free or paid?

Firefox Devtools MCP operates under a Free / Open Source model (No auth required). Zen MCP operates under a Free / Open Source model (No auth required).

Which MCP server has more tools and community activity?

Firefox Devtools MCP lists 4 tools with 2 views and 417 GitHub stars. Zen MCP lists 6 tools with 2 views and 18 GitHub stars.

Can I use both Firefox Devtools MCP and Zen MCP together in the same MCP host?

Yes! MCP hosts like Claude Desktop, Cursor, Windsurf, Cline, and VS Code support configuring multiple servers under the mcpServers object simultaneously.

Side-by-Side Model Context Protocol Comparison

Firefox Devtools MCP vs Zen MCP

In-depth architectural comparison of the Firefox Devtools MCP and Zen MCP MCP servers. Compare execution transports, security boundaries, tool capabilities, quality scores, and ready-to-paste client installation snippets for Claude, Cursor, Windsurf, and VS Code.

At a Glance & Executive Verdict

Firefox Devtools MCP

Browser Automation · Local stdio

Quality: 63/100 (Good) | Auth: No auth required

Zen MCP

Browser Automation · Local stdio

Quality: 43/100 (Fair) | Auth: No auth required

Verdict Summary: Choose Firefox Devtools MCP if you need specialized Browser Automation tools running via a local process. Choose Zen MCP if your workspace requires Browser Automation integration with local subprocess execution. Both servers can be configured concurrently in your client's mcpServers manifest.

Which MCP Server Should You Choose?

Choose Firefox Devtools MCP when:

You need dedicated capabilities in the Browser Automation domain.
You prefer local stdio subprocess transport architecture.
Your security boundary fits: No auth required (Free / Open Source).
You have access to required keys: START_URL, FIREFOX_HEADLESS, ACCEPT_INSECURE_CERTS, CONNECT_EXISTING, MARIONETTE_PORT, TOOL_PRESET, ENABLE_SCRIPT, ENABLE_PRIVILEGED_CONTEXT.
Primary tools included: slim, developer, mozilla.

Explore Firefox Devtools MCP Details

Choose Zen MCP when:

You need dedicated capabilities in the Browser Automation domain.
You prefer local stdio subprocess transport architecture.
Your security boundary fits: No auth required (Free / Open Source).
You have access to required keys: ZEN_DEBUG_PORT.
Primary tools included: .

Feature & Specification Comparison

Specification	Firefox Devtools MCP freema Browser Automation	Zen MCP sh6drack Browser Automation
Summary	Firefox browser automation via WebDriver BiDi for testing, scraping, and browser control. Supports snapshot/UID-based interactions, network monitoring, console capture, and screenshots.	Zen Browser automation via WebDriver BiDi. 20 tools for navigation, form filling, screenshots, and JavaScript evaluation. No Selenium or Playwright required.
Category & Scope

Tools & Capabilities Breakdown

Firefox Devtools MCP Tools (4)

slim

`pages`, `snapshot`, `input`, `screenshot`

developer

`basic` plus `debugging`, `network`, `console`, `profiler`

mozilla

`developer` plus `prefs`, `privileged`

all

every module

Zen MCP Tools (6)

20 browser automation tools including navigation, form filling, and screenshots

Direct WebDriver BiDi protocol communication over WebSocket

Ready-to-Paste Client Configurations

Paste either (or both) of these JSON server blocks into your client config file (e.g. claude_desktop_config.json or ~/.cursor/mcp.json).

Firefox Devtools MCP Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "freema-firefox-devtools-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@mozilla/firefox-devtools-mcp@latest"
      ],
      "env": {
        "START_URL": "YOUR_START_URL_HERE",
        "FIREFOX_HEADLESS": "YOUR_FIREFOX_HEADLESS_HERE",
        "ACCEPT_INSECURE_CERTS": "YOUR_ACCEPT_INSECURE_CERTS_HERE",
        "CONNECT_EXISTING": "YOUR_CONNECT_EXISTING_HERE",
        "MARIONETTE_PORT": "YOUR_MARIONETTE_PORT_HERE",
        "TOOL_PRESET": "YOUR_TOOL_PRESET_HERE",
        "ENABLE_SCRIPT": "YOUR_ENABLE_SCRIPT_HERE",
        "ENABLE_PRIVILEGED_CONTEXT": "YOUR_ENABLE_PRIVILEGED_CONTEXT_HERE"
      }
    }
  }
}

Zen MCP Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "sh6drack-zen-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "sh6drack-zen-mcp"
      ],
      "env": {
        "ZEN_DEBUG_PORT": "YOUR_ZEN_DEBUG_PORT_HERE"
      }
    }
  }
}

Frequently Asked Questions

Firefox Devtools MCP is categorized under Browser Automation and uses a local stdio subprocess. In contrast, Zen MCP belongs to Browser Automation using local stdio subprocess. Select Firefox Devtools MCP when you need capabilities focused on browser automation and Zen MCP when you require tools for browser automation.

More alternatives to Firefox Devtools MCP More alternatives to Zen MCP Browser Automation category hub