We show you how to connect the GTmetrix MCP with Claude.

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Overview

The GTmetrix MCP can be connected to Claude in order to integrate GTmetrix workflow directly into Claude.

In this guide, we’ll show you how to connect the GTmetrix MCP to Claude with step-by-step instructions.

 

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Connecting GTmetrix MCP to Claude

There are 3 primary ways to connect the GTmetrix MCP to Claude:

• Using OAuth on Claude Desktop/Browser
• Using JSON on Claude Desktop
• Command line for Claude CLI

We provide step-by-step guidance for each method below:
 

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Using OAuth on Claude Desktop/Browser

The simplest and quickest method to connect to the GTmetrix MCP is by using OAuth – you can connect with just a few clicks.

Note that the connection procedure is the same on both the desktop app and the browser version.
 

1) Click Customize on the Sidebar

 

 

2) Click Connectors, then the “+” button on the top right

 

 

3) Click “Add custom connector”

 

 

4) Enter MCP details

Name: GTmetrix
Remote MCP server URL: https://gtmetrix.com/mcp

No Advanced settings needed, so they leave those as-is. Click Add once you’ve entered the required details.
 

 

5) Click the Connect button

Link your GTmetrix Account by clicking the Connect button. This will launch a new browser window asking you to log into GTmetrix.
 

 

6) Authorize your Connection

• Log into your GTmetrix account
• Click Allow to authorize your connection

 

 
A success screen should appear when the connection is successfully established.
 

 

7) Restart/Open Claude

You’ll see the GTmetrix MCP now active with various tools.
 

 

8) Confirm Connection

To confirm, start a new chat and ask Claude if it can see the GTmetrix MCP tools.
 

 
If Claude responds with a list of GTmetrix tools, you know that the connection was successful and you can now start interacting with Claude and get it to use GTmetrix.
 

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Using JSON on Claude Desktop

If you prefer to manually configure the GTmetrix MCP server in your Claude Desktop configuration files, you can do so with the instructions below.

Note: These instructions are for Windows devices only – For Mac/Linux, please use our General Instructions prompt.
 

1) Generate a GTmetrix API key

Using a JSON config to connect to the GTmetrix MCP requires an API Key. Go to your GTmetrix Account page and click Generate API Key if you don’t already have one.
 

 
Copy your API key and keep it aside safely as you’ll need it to set up the MCP connection.
 

 
For security reasons, the screenshot above says YOUR_API_KEY but your Account page will display your actual API key.
 

2) Install Node.js

Claude Desktop requires Node.js to be installed to execute npx and mcp-remote commands.
Download Node.js and install it for your appropriate OS.

 

3) Open Claude Desktop and go to Settings → Developer

 

 

4) Click Edit Config and locate the claude_desktop_config.json file

 

 
Windows Explorer will pop up and display the location of the claude_desktop_config.json file
 

 

5) Edit the claude_desktop_config.json file

Open the claude_desktop_config.json file with a text editor.

Note that this config file may already contain other code – so be mindful of brackets.

Add the below code inside the global {}. The main JSON code should be within the "mcpservers":{}.

 "mcpServers": {
    "gtmetrix": {
      "command": "cmd",
      "args": [
        "/c",
        "npx",
        "-y",
        "[email protected]",
        "https://gtmetrix.com/mcp",
        "--header",
        "Authorization: Bearer YOUR_API_KEY"
      ]
    }
  }

where YOUR_API_KEY is the API key you copied from your Account page.

Read our troubleshooting guide for JSON formatting if you’re having issues.

 

6) Save the config file and restart Claude Desktop

Save the config file, then quit the Claude Desktop app entirely and restart it to apply the changes (for browser, close the tab and open a new Claude session).

 

 

7) Confirm Connection

Start a new chat and ask Claude if it can see the GTmetrix MCP tools.
 

 
If Claude responds with a list of GTmetrix tools, that is confirmation that the connection was successful, and you can now start interacting with Claude and get it to use GTmetrix.
 

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Command line for Claude CLI

Use this command in your terminal to install the GTmetrix MCP server with Claude CLI:

claude mcp add gtmetrix https://gtmetrix.com/mcp --transport http --header "Authorization: Bearer YOUR_API_KEY"

Replace YOUR_API_KEY with the API Key generated from your Account page.

 

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Troubleshooting

Try these tips if you’re encountering issues connecting with the GTmetrix MCP.

 

1) Ensure you restart Claude Desktop properly

After connecting to the GTmetrix MCP (or editing the config file), make sure to quit the App entirely (close the window, quit the app from your taskbar, etc.) and restart to apply the changes.

For Claude Browser, close and reopen the tab to start a new session.
 

2) JSON editing tips/caveats

If you’re editing your JSON config file to connect to the GTmetrix MCP, note some caveats:

 

a) You may need to flush your npx cache

You can use command npm cache clean --force to do so
Verify with command npm cache verify that the cache is empty

 

b) Mind the curly brackets } and commas

You must ensure that the mcpServer block adheres to the structure/content already in place of your config file

1. Ensure your code is within the first bracket of the JSON file
2. If you do not have an "mcpServers": {...} section, you can add the entire block to the top (in pink)
   • Ensure a comma is added in the last bracket },
3. The GTmetrix MCP code (in blue) should be inside the "mcpServers" : {...} section
4. Save and restart Claude

 

c) The provided JSON code is specific to Claude Desktop on Windows

If you’re on a Mac or Linux machine, or if you’re facing general issues with the JSON config setup, we’d suggest copying the General Instructions Prompt on the Account page:

• Visit your Account page and locate the MCP Setup dropdown
• Select “JSON with API key” from the dropdown, then copy the prompt and paste it in Claude to get setup instructions
• Note that as a security measure, the screenshot below shows YOUR_API_KEY, in place of the actual API key shown on your Account page
• When pasting the prompt in Claude, make sure not to paste your actual API key – your API key should only be used in the code that you insert in the JSON file

 

 
Follow the instructions your AI tool provides to get up and running with the GTmetrix MCP.

 

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Summary

Connecting the GTmetrix MCP to Claude is quick, simple, and can be done in multiple ways:

• Oauth authentication
• Editing the JSON config
• Command Line Interface (CLI)

Use the GTmetrix MCP connection to bring your GTmetrix workflows directly into Claude.

Get Claude to start GTmetrix tests, test in different scenarios (locations/devices/connection speeds, etc.), compare results, and help you understand what’s slowing down your page and how to fix them.

Give this a try and let us know if you run into any bugs or issues.

 

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