npm package: @nimbus21.ai/chrome-devtools-mcp
Description: MCP server for Chrome DevTools with stealth mode support
Author: NIMBUS21
Latest version: 0.17.7

# Chrome DevTools MCP - Enhanced by NIMBUS21

[![npm @nimbus21.ai/chrome-devtools-mcp package](https://img.shields.io/npm/v/@nimbus21.ai/chrome-devtools-mcp.svg)](https://npmjs.org/package/@nimbus21.ai/chrome-devtools-mcp)

> **Note:** This is an **unofficial community-maintained fork** of the original Chrome DevTools MCP server, enhanced and modified by the **NIMBUS21 Team**. This package is not affiliated with or endorsed by Google or the Chrome DevTools team.

## 🚀 Powered by NIMBUS21

This enhanced version is brought to you by **[NIMBUS21](https://nimbus21.com)** - a leading technology innovation company specializing in AI-powered automation, browser automation solutions, and enterprise software development. Visit [nimbus21.com](https://nimbus21.com) to explore our cutting-edge AI tools, automation platforms, and developer services.

**NIMBUS21** delivers advanced browser automation frameworks, intelligent testing solutions, and AI-driven development tools for modern web applications. Our expertise in Chrome automation, DevTools integration, and Model Context Protocol (MCP) implementations helps developers and enterprises build more reliable, performant, and intelligent software solutions.

---

`@nimbus21.ai/chrome-devtools-mcp` lets your coding agent (such as Gemini, Claude, Cursor or Copilot)
control and inspect a live Chrome browser. It acts as a Model-Context-Protocol
(MCP) server, giving your AI coding assistant access to the full power of
Chrome DevTools for reliable automation, in-depth debugging, and performance analysis.

## [Tool reference](./docs/tool-reference.md) | [Changelog](./CHANGELOG.md) | [Contributing](./CONTRIBUTING.md) | [Troubleshooting](./docs/troubleshooting.md) | [Design Principles](./docs/design-principles.md)

## Key features

- **Get performance insights**: Uses [Chrome
  DevTools](https://github.com/ChromeDevTools/devtools-frontend) to record
  traces and extract actionable performance insights.
- **Advanced browser debugging**: Analyze network requests, take screenshots and
  check browser console messages (with source-mapped stack traces).
- **Reliable automation**. Uses
  [puppeteer](https://github.com/puppeteer/puppeteer) to automate actions in
  Chrome and automatically wait for action results.

## Disclaimers

`chrome-devtools-mcp` exposes content of the browser instance to the MCP clients
allowing them to inspect, debug, and modify any data in the browser or DevTools.
Avoid sharing sensitive or personal information that you don't want to share with
MCP clients.

Performance tools may send trace URLs to the Google CrUX API to fetch real-user
experience data. This helps provide a holistic performance picture by
presenting field data alongside lab data. This data is collected by the [Chrome
User Experience Report (CrUX)](https://developer.chrome.com/docs/crux). To disable
this, run with the `--no-performance-crux` flag.

## **Usage statistics**

Google collects usage statistics (such as tool invocation success rates, latency, and environment information) to improve the reliability and performance of Chrome DevTools MCP.

Data collection is **enabled by default**. You can opt-out by passing the `--no-usage-statistics` flag when starting the server:

```json
"args": ["-y", "chrome-devtools-mcp@latest", "--no-usage-statistics"]
```

Google handles this data in accordance with the [Google Privacy Policy](https://policies.google.com/privacy).

Google's collection of usage statistics for Chrome DevTools MCP is independent from the Chrome browser's usage statistics. Opting out of Chrome metrics does not automatically opt you out of this tool, and vice-versa.

Collection is disabled if CHROME_DEVTOOLS_MCP_NO_USAGE_STATISTICS or CI env variables are set.

## Requirements

- [Node.js](https://nodejs.org/) v20.19 or a newer [latest maintenance LTS](https://github.com/nodejs/Release#release-schedule) version.
- [Chrome](https://www.google.com/chrome/) current stable version or newer.
- [npm](https://www.npmjs.com/).

## Getting started

Add the following config to your MCP client:

```json
{
  "mcpServers": {
    "chrome-devtools": {
      "command": "npx",
      "args": ["-y", "@nimbus21.ai/chrome-devtools-mcp@latest"]
    }
  }
}
```

> [!NOTE]
> Using `@nimbus21.ai/chrome-devtools-mcp@latest` ensures that your MCP client will always use the latest version of the NIMBUS21-enhanced Chrome DevTools MCP server.

### MCP Client configuration

<details>
  <summary>Amp</summary>
  Follow https://ampcode.com/manual#mcp and use the config provided above. You can also install the Chrome DevTools MCP server using the CLI:

```bash
amp mcp add chrome-devtools -- npx chrome-devtools-mcp@latest
```

</details>

<details>
  <summary>Antigravity</summary>

To use the Chrome DevTools MCP server follow the instructions from <a href="https://antigravity.google/docs/mcp">Antigravity's docs</a> to install a custom MCP server. Add the following config to the MCP servers config:

```bash
{
  "mcpServers": {
    "chrome-devtools": {
      "command": "npx",
      "args": [
        "chrome-devtools-mcp@latest",
        "--browser-url=http://127.0.0.1:9222",
        "-y"
      ]
    }
  }
}
```

This will make the Chrome DevTools MCP server automatically connect to the browser that Antigravity is using. If you are not using port 9222, make sure to adjust accordingly.

Chrome DevTools MCP will not start the browser instance automatically using this approach as as the Chrome DevTools MCP server runs in Antigravity's built-in browser. If the browser is not already running, you have to start it first by clicking the Chrome icon at the top right corner.

</details>

<details>
  <summary>Claude Code</summary>

**Install via CLI (MCP only)**

Use the Claude Code CLI to add the Chrome DevTools MCP server (<a href="https://code.claude.com/docs/en/mcp">guide</a>):

```bash
claude mcp add chrome-devtools --scope user npx @nimbus21.ai/chrome-devtools-mcp@latest
```

**Install as a Plugin (MCP + Skills)**

> [!NOTE]  
> If you already had Chrome DevTools MCP installed previously for Claude Code, make sure to remove it first from your installation and configuration files.

To install Chrome DevTools MCP with skills, add the marketplace registry in Claude Code:

```sh
/plugin marketplace add ChromeDevTools/chrome-devtools-mcp
```

Then, install the plugin:

```sh
/plugin install chrome-devtools-mcp
```

Restart Claude Code to have the MCP server and skills load (check with `/skills`).

</details>

<details>
  <summary>Cline</summary>
  Follow https://docs.cline.bot/mcp/configuring-mcp-servers and use the config provided above.
</details>

<details>
  <summary>Codex</summary>
  Follow the <a href="https://developers.openai.com/codex/mcp/#configure-with-the-cli">configure MCP guide</a>
  using the standard config from above. You can also install the Chrome DevTools MCP server using the Codex CLI:

```bash
codex mcp add chrome-devtools -- npx @nimbus21.ai/chrome-devtools-mcp@latest
```

**On Windows 11**

Configure the Chrome install location and increase the startup timeout by updating `.codex/config.toml` and adding the following `env` and `startup_timeout_ms` parameters:

```
[mcp_servers.chrome-devtools]
command = "cmd"
args = [
    "/c",
    "npx",
    "-y",
    "@nimbus21.ai/chrome-devtools-mcp@latest",
]
env = { SystemRoot="C:\\Windows", PROGRAMFILES="C:\\Program Files" }
startup_timeout_ms = 20_000
```

</details>

<details>
  <summary>Copilot CLI</summary>

Start Copilot CLI:

```
copilot
```

Start the dialog to add a new MCP server by running:

```
/mcp add
```

Configure the following fields and press `CTRL+S` to save the configuration:

- **Server name:** `chrome-devtools`
- **Server Type:** `[1] Local`
- **Command:** `npx`
- **Arguments:** `-y, @nimbus21.ai/chrome-devtools-mcp@latest`

</details>

<details>
  <summary>Copilot / VS Code</summary>

Follow the MCP install <a href="https://code.visualstudio.com/docs/copilot/chat/mcp-servers#_add-an-mcp-server">guide</a>,
with the standard config from above. You can also install the Chrome DevTools MCP server using the VS Code CLI:

```bash
code --add-mcp '{"name":"chrome-devtools","command":"npx","args":["@nimbus21.ai/chrome-devtools-mcp@latest"]}'
```

</details>

<details>
  <summary>Cursor</summary>

**Click the button to install:**

[<img src="https://cursor.com/deeplink/mcp-install-dark.svg" alt="Install in Cursor">](https://cursor.com/en/install-mcp?name=chrome-devtools&config=eyJjb21tYW5kIjoibnB4IC15IEBuaW1idXMyMS5haS9jaHJvbWUtZGV2dG9vbHMtbWNwQGxhdGVzdCJ9)

**Or install manually:**

Go to `Cursor Settings` -> `MCP` -> `New MCP Server`. Use the config provided above.

</details>

<details>
  <summary>Factory CLI</summary>
Use the Factory CLI to add the Chrome DevTools MCP server (<a href="https://docs.factory.ai/cli/configuration/mcp">guide</a>):

```bash
droid mcp add chrome-devtools "npx -y chrome-devtools-mcp@latest"
```

</details>

<details>
  <summary>Gemini CLI</summary>
Install the Chrome DevTools MCP server using the Gemini CLI.

**Project wide:**

```bash
# Either MCP only:
gemini mcp add chrome-devtools npx @nimbus21.ai/chrome-devtools-mcp@latest
# Or as a Gemini extension (MCP+Skills):
gemini extensions install --auto-update https://github.com/ChromeDevTools/chrome-devtools-mcp
```

**Globally:**

```bash
gemini mcp add -s user chrome-devtools npx @nimbus21.ai/chrome-devtools-mcp@latest
```

Alternatively, follow the <a href="https://github.com/google-gemini/gemini-cli/blob/main/docs/tools/mcp-server.md#how-to-set-up-your-mcp-server">MCP guide</a> and use the standard config from above.

</details>

<details>
  <summary>Gemini Code Assist</summary>
  Follow the <a href="https://cloud.google.com/gemini/docs/codeassist/use-agentic-chat-pair-programmer#configure-mcp-servers">configure MCP guide</a>
  using the standard config from above.
</details>

<details>
  <summary>JetBrains AI Assistant & Junie</summary>

Go to `Settings | Tools | AI Assistant | Model Context Protocol (MCP)` -> `Add`. Use the config provided above.
The same way chrome-devtools-mcp can be configured for JetBrains Junie in `Settings | Tools | Junie | MCP Settings` -> `Add`. Use the config provided above.

</details>

<details>
  <summary>Kiro</summary>

In **Kiro Settings**, go to `Configure MCP` > `Open Workspace or User MCP Config` > Use the configuration snippet provided above.

Or, from the IDE **Activity Bar** > `Kiro` > `MCP Servers` > `Click Open MCP Config`. Use the configuration snippet provided above.

</details>

<details>
  <summary>Katalon Studio</summary>

The Chrome DevTools MCP server can be used with <a href="https://docs.katalon.com/katalon-studio/studioassist/mcp-servers/setting-up-chrome-devtools-mcp-server-for-studioassist">Katalon StudioAssist</a> via an MCP proxy.

**Step 1:** Install the MCP proxy by following the <a href="https://docs.katalon.com/katalon-studio/studioassist/mcp-servers/setting-up-mcp-proxy-for-stdio-mcp-servers">MCP proxy setup guide</a>.

**Step 2:** Start the Chrome DevTools MCP server with the proxy:

```bash
mcp-proxy --transport streamablehttp --port 8080 -- npx -y chrome-devtools-mcp@latest
```

**Note:** You may need to pick another port if 8080 is already in use.

**Step 3:** In Katalon Studio, add the server to StudioAssist with the following settings:

- **Connection URL:** `http://127.0.0.1:8080/mcp`
- **Transport type:** `HTTP`

Once connected, the Chrome DevTools MCP tools will be available in StudioAssist.

</details>

<details>
  <summary>OpenCode</summary>

Add the following configuration to your `opencode.json` file. If you don't have one, create it at `~/.config/opencode/opencode.json` (<a href="https://opencode.ai/docs/mcp-servers">guide</a>):

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "chrome-devtools": {
      "type": "local",
      "command": ["npx", "-y", "chrome-devtools-mcp@latest"]
    }
  }
}
```

</details>

<details>
  <summary>Qoder</summary>

In **Qoder Settings**, go to `MCP Server` > `+ Add` > Use the configuration snippet provided above.

Alternatively, follow the <a href="https://docs.qoder.com/user-guide/chat/model-context-protocol">MCP guide</a> and use the standard config from above.

</details>

<details>
  <summary>Qoder CLI</summary>

Install the Chrome DevTools MCP server using the Qoder CLI (<a href="https://docs.qoder.com/cli/using-cli#mcp-servsers">guide</a>):

**Project wide:**

```bash
qodercli mcp add chrome-devtools -- npx chrome-devtools-mcp@latest
```

**Globally:**

```bash
qodercli mcp add -s user chrome-devtools -- npx chrome-devtools-mcp@latest
```

</details>

<details>
  <summary>Visual Studio</summary>
  
  **Click the button to install:**
  
  [<img src="https://img.shields.io/badge/Visual_Studio-Install-C16FDE?logo=visualstudio&logoColor=white" alt="Install in Visual Studio">](https://vs-open.link/mcp-install?%7B%22name%22%3A%22chrome-devtools%22%2C%22command%22%3A%22npx%22%2C%22args%22%3A%5B%22@nimbus21.ai/chrome-devtools-mcp%40latest%22%5D%7D)
</details>

<details>
  <summary>Warp</summary>

Go to `Settings | AI | Manage MCP Servers` -> `+ Add` to [add an MCP Server](https://docs.warp.dev/knowledge-and-collaboration/mcp#adding-an-mcp-server). Use the config provided above.

</details>

<details>
  <summary>Windsurf</summary>
  Follow the <a href="https://docs.windsurf.com/windsurf/cascade/mcp#mcp-config-json">configure MCP guide</a>
  using the standard config from above.
</details>

### Your first prompt

Enter the following prompt in your MCP Client to check if everything is working:

```
Check the performance of https://developers.chrome.com
```

Your MCP client should open the browser and record a performance trace.

> [!NOTE]  
> The MCP server will start the browser automatically once the MCP client uses a tool that requires a running browser instance. Connecting to the Chrome DevTools MCP server on its own will not automatically start the browser.

## Tools

If you run into any issues, checkout our [troubleshooting guide](./docs/troubleshooting.md).

<!-- BEGIN AUTO GENERATED TOOLS -->

- **Input automation** (8 tools)
  - [`click`](docs/tool-reference.md#click)
  - [`drag`](docs/tool-reference.md#drag)
  - [`fill`](docs/tool-reference.md#fill)
  - [`fill_form`](docs/tool-reference.md#fill_form)
  - [`handle_dialog`](docs/tool-reference.md#handle_dialog)
  - [`hover`](docs/tool-reference.md#hover)
  - [`press_key`](docs/tool-reference.md#press_key)
  - [`upload_file`](docs/tool-reference.md#upload_file)
- **Navigation automation** (6 tools)
  - [`close_page`](docs/tool-reference.md#close_page)
  - [`list_pages`](docs/tool-reference.md#list_pages)
  - [`navigate_page`](docs/tool-reference.md#navigate_page)
  - [`new_page`](docs/tool-reference.md#new_page)
  - [`select_page`](docs/tool-reference.md#select_page)
  - [`wait_for`](docs/tool-reference.md#wait_for)
- **Emulation** (2 tools)
  - [`emulate`](docs/tool-reference.md#emulate)
  - [`resize_page`](docs/tool-reference.md#resize_page)
- **Performance** (3 tools)
  - [`performance_analyze_insight`](docs/tool-reference.md#performance_analyze_insight)
  - [`performance_start_trace`](docs/tool-reference.md#performance_start_trace)
  - [`performance_stop_trace`](docs/tool-reference.md#performance_stop_trace)
- **Network** (2 tools)
  - [`get_network_request`](docs/tool-reference.md#get_network_request)
  - [`list_network_requests`](docs/tool-reference.md#list_network_requests)
- **Debugging** (5 tools)
  - [`evaluate_script`](docs/tool-reference.md#evaluate_script)
  - [`get_console_message`](docs/tool-reference.md#get_console_message)
  - [`list_console_messages`](docs/tool-reference.md#list_console_messages)
  - [`take_screenshot`](docs/tool-reference.md#take_screenshot)
  - [`take_snapshot`](docs/tool-reference.md#take_snapshot)

<!-- END AUTO GENERATED TOOLS -->

## Configuration

The Chrome DevTools MCP server supports the following configuration option:

<!-- BEGIN AUTO GENERATED OPTIONS -->

- **`--autoConnect`/ `--auto-connect`**
  If specified, automatically connects to a browser (Chrome 144+) running in the user data directory identified by the channel param. Requires the remoted debugging server to be started in the Chrome instance via chrome://inspect/#remote-debugging.
  - **Type:** boolean
  - **Default:** `false`

- **`--browserUrl`/ `--browser-url`, `-u`**
  Connect to a running, debuggable Chrome instance (e.g. `http://127.0.0.1:9222`). For more details see: https://github.com/ChromeDevTools/chrome-devtools-mcp#connecting-to-a-running-chrome-instance.
  - **Type:** string

- **`--wsEndpoint`/ `--ws-endpoint`, `-w`**
  WebSocket endpoint to connect to a running Chrome instance (e.g., ws://127.0.0.1:9222/devtools/browser/<id>). Alternative to --browserUrl.
  - **Type:** string

- **`--wsHeaders`/ `--ws-headers`**
  Custom headers for WebSocket connection in JSON format (e.g., '{"Authorization":"Bearer token"}'). Only works with --wsEndpoint.
  - **Type:** string

- **`--headless`**
  Whether to run in headless (no UI) mode.
  - **Type:** boolean
  - **Default:** `false`

- **`--executablePath`/ `--executable-path`, `-e`**
  Path to custom Chrome executable.
  - **Type:** string

- **`--isolated`**
  If specified, creates a temporary user-data-dir that is automatically cleaned up after the browser is closed. Defaults to false.
  - **Type:** boolean

- **`--userDataDir`/ `--user-data-dir`**
  Path to the user data directory for Chrome. Default is $HOME/.cache/chrome-devtools-mcp/chrome-profile$CHANNEL_SUFFIX_IF_NON_STABLE
  - **Type:** string

- **`--channel`**
  Specify a different Chrome channel that should be used. The default is the stable channel version.
  - **Type:** string
  - **Choices:** `stable`, `canary`, `beta`, `dev`

- **`--logFile`/ `--log-file`**
  Path to a file to write debug logs to. Set the env variable `DEBUG` to `*` to enable verbose logs. Useful for submitting bug reports.
  - **Type:** string

- **`--viewport`**
  Initial viewport size for the Chrome instances started by the server. For example, `1280x720`. In headless mode, max size is 3840x2160px.
  - **Type:** string

- **`--proxyServer`/ `--proxy-server`**
  Proxy server configuration for Chrome passed as --proxy-server when launching the browser. See https://www.chromium.org/developers/design-documents/network-settings/ for details.
  - **Type:** string

- **`--acceptInsecureCerts`/ `--accept-insecure-certs`**
  If enabled, ignores errors relative to self-signed and expired certificates. Use with caution.
  - **Type:** boolean

- **`--stealth`**
  Enable stealth mode to avoid bot detection. Uses puppeteer-extra-plugin-stealth and adds anti-detection Chrome arguments.
  - **Type:** boolean
  - **Default:** `false`

- **`--chromeArgs`/ `--chrome-args`**
  Additional Chrome arguments to pass to the browser (comma-separated). Example: --chromeArgs="--disable-gpu,--no-sandbox"
  - **Type:** string

- **`--chromeArg`/ `--chrome-arg`**
  Additional arguments for Chrome. Only applies when Chrome is launched by chrome-devtools-mcp.
  - **Type:** array

- **`--ignoreDefaultChromeArg`/ `--ignore-default-chrome-arg`**
  Explicitly disable default arguments for Chrome. Only applies when Chrome is launched by chrome-devtools-mcp.
  - **Type:** array

- **`--categoryEmulation`/ `--category-emulation`**
  Set to false to exclude tools related to emulation.
  - **Type:** boolean
  - **Default:** `true`

- **`--categoryPerformance`/ `--category-performance`**
  Set to false to exclude tools related to performance.
  - **Type:** boolean
  - **Default:** `true`

- **`--categoryNetwork`/ `--category-network`**
  Set to false to exclude tools related to network.
  - **Type:** boolean
  - **Default:** `true`

- **`--performanceCrux`/ `--performance-crux`**
  Set to false to disable sending URLs from performance traces to CrUX API to get field performance data.
  - **Type:** boolean
  - **Default:** `true`

- **`--usageStatistics`/ `--usage-statistics`**
  Set to false to opt-out of usage statistics collection. Google collects usage data to improve the tool, handled under the Google Privacy Policy (https://policies.google.com/privacy). This is independent from Chrome browser metrics. Disabled if CHROME_DEVTOOLS_MCP_NO_USAGE_STATISTICS or CI env variables are set.
  - **Type:** boolean
  - **Default:** `true`

<!-- END AUTO GENERATED OPTIONS -->

Pass them via the `args` property in the JSON configuration. For example:

```json
{
  "mcpServers": {
    "chrome-devtools": {
      "command": "npx",
      "args": [
        "@nimbus21.ai/chrome-devtools-mcp@latest",
        "--channel=canary",
        "--headless=true",
        "--isolated=true"
      ]
    }
  }
}
```

### Connecting via WebSocket with custom headers

You can connect directly to a Chrome WebSocket endpoint and include custom headers (e.g., for authentication):

```json
{
  "mcpServers": {
    "chrome-devtools": {
      "command": "npx",
      "args": [
        "@nimbus21.ai/chrome-devtools-mcp@latest",
        "--wsEndpoint=ws://127.0.0.1:9222/devtools/browser/<id>",
        "--wsHeaders={\"Authorization\":\"Bearer YOUR_TOKEN\"}"
      ]
    }
  }
}
```

To get the WebSocket endpoint from a running Chrome instance, visit `http://127.0.0.1:9222/json/version` and look for the `webSocketDebuggerUrl` field.

You can also run `npx @nimbus21.ai/chrome-devtools-mcp@latest --help` to see all available configuration options.

## Concepts

### User data directory

`chrome-devtools-mcp` starts a Chrome's stable channel instance using the following user
data directory:

- Linux / macOS: `$HOME/.cache/chrome-devtools-mcp/chrome-profile-$CHANNEL`
- Windows: `%HOMEPATH%/.cache/chrome-devtools-mcp/chrome-profile-$CHANNEL`

The user data directory is not cleared between runs and shared across
all instances of `chrome-devtools-mcp`. Set the `isolated` option to `true`
to use a temporary user data dir instead which will be cleared automatically after
the browser is closed.

### Connecting to a running Chrome instance

By default, the Chrome DevTools MCP server will start a new Chrome instance with a dedicated profile. This might not be ideal in all situations:

- If you would like to maintain the same application state when alternating between manual site testing and agent-driven testing.
- When the MCP needs to sign into a website. Some accounts may prevent sign-in when the browser is controlled via WebDriver (the default launch mechanism for the Chrome DevTools MCP server).
- If you're running your LLM inside a sandboxed environment, but you would like to connect to a Chrome instance that runs outside the sandbox.

In these cases, start Chrome first and let the Chrome DevTools MCP server connect to it. There are two ways to do so:

- **Automatic connection (available in Chrome 144)**: best for sharing state between manual and agent-driven testing.
- **Manual connection via remote debugging port**: best when running inside a sandboxed environment.

#### Automatically connecting to a running Chrome instance

**Step 1:** Set up remote debugging in Chrome

In Chrome (\>= M144), do the following to set up remote debugging:

1.  Navigate to `chrome://inspect/#remote-debugging` to enable remote debugging.
2.  Follow the dialog UI to allow or disallow incoming debugging connections.

**Step 2:** Configure Chrome DevTools MCP server to automatically connect to a running Chrome Instance

To connect the `chrome-devtools-mcp` server to the running Chrome instance, use
`--autoConnect` command line argument for the MCP server.

The following code snippet is an example configuration for gemini-cli:

```json
{
  "mcpServers": {
    "chrome-devtools": {
      "command": "npx",
      "args": ["chrome-devtools-mcp@latest", "--autoConnect"]
    }
  }
}
```

**Step 3:** Test your setup

Make sure your browser is running. Open gemini-cli and run the following prompt:

```none
Check the performance of https://developers.chrome.com
```

> [!NOTE]  
> The <code>autoConnect</code> option requires the user to start Chrome. If the user has multiple active profiles, the MCP server will connect to the default profile (as determined by Chrome). The MCP server has access to all open windows for the selected profile.

The Chrome DevTools MCP server will try to connect to your running Chrome
instance. It shows a dialog asking for user permission.

Clicking **Allow** results in the Chrome DevTools MCP server opening
[developers.chrome.com](http://developers.chrome.com) and taking a performance
trace.

#### Manual connection using port forwarding

You can connect to a running Chrome instance by using the `--browser-url` option. This is useful if you are running the MCP server in a sandboxed environment that does not allow starting a new Chrome instance.

Here is a step-by-step guide on how to connect to a running Chrome instance:

**Step 1: Configure the MCP client**

Add the `--browser-url` option to your MCP client configuration. The value of this option should be the URL of the running Chrome instance. `http://127.0.0.1:9222` is a common default.

```json
{
  "mcpServers": {
    "chrome-devtools": {
      "command": "npx",
      "args": [
        "chrome-devtools-mcp@latest",
        "--browser-url=http://127.0.0.1:9222"
      ]
    }
  }
}
```

**Step 2: Start the Chrome browser**

> [!WARNING]  
> Enabling the remote debugging port opens up a debugging port on the running browser instance. Any application on your machine can connect to this port and control the browser. Make sure that you are not browsing any sensitive websites while the debugging port is open.

Start the Chrome browser with the remote debugging port enabled. Make sure to close any running Chrome instances before starting a new one with the debugging port enabled. The port number you choose must be the same as the one you specified in the `--browser-url` option in your MCP client configuration.

For security reasons, [Chrome requires you to use a non-default user data directory](https://developer.chrome.com/blog/remote-debugging-port) when enabling the remote debugging port. You can specify a custom directory using the `--user-data-dir` flag. This ensures that your regular browsing profile and data are not exposed to the debugging session.

**macOS**

```bash
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --remote-debugging-port=9222 --user-data-dir=/tmp/chrome-profile-stable
```

**Linux**

```bash
/usr/bin/google-chrome --remote-debugging-port=9222 --user-data-dir=/tmp/chrome-profile-stable
```

**Windows**

```bash
"C:\Program Files\Google\Chrome\Application\chrome.exe" --remote-debugging-port=9222 --user-data-dir="%TEMP%\chrome-profile-stable"
```

**Step 3: Test your setup**

After configuring the MCP client and starting the Chrome browser, you can test your setup by running a simple prompt in your MCP client:

```
Check the performance of https://developers.chrome.com
```

Your MCP client should connect to the running Chrome instance and receive a performance report.

If you hit VM-to-host port forwarding issues, see the “Remote debugging between virtual machine (VM) and host fails” section in [`docs/troubleshooting.md`](./docs/troubleshooting.md#remote-debugging-between-virtual-machine-vm-and-host-fails).

For more details on remote debugging, see the [Chrome DevTools documentation](https://developer.chrome.com/docs/devtools/remote-debugging/).

### Debugging Chrome on Android

Please consult [these instructions](./docs/debugging-android.md).

## Known limitations

See [Troubleshooting](./docs/troubleshooting.md).