Lighthouse MCP Server


A Model Context Protocol (MCP) server that provides comprehensive web performance auditing and analysis capabilities using Google Lighthouse. This server enables LLMs and AI agents to perform detailed website performance assessments, accessibility audits, SEO analysis, security checks, and Core Web Vitals monitoring.

🌟 Key Features

- 🚀 Performance Analysis: Complete Lighthouse audits with Core Web Vitals, performance scores, and optimization recommendations
- ♿ Accessibility Audits: WCAG compliance checking and accessibility score analysis
- 🔍 SEO Analysis: Search engine optimization audits and best practice recommendations
- 🔒 Security Assessment: HTTPS, CSP, and security vulnerability scanning
- 📊 Resource Analysis: JavaScript, CSS, image, and font optimization opportunities
- 📱 Mobile vs Desktop: Comparative analysis across devices with throttling options
- ⚡ Core Web Vitals: LCP, FID, CLS monitoring with threshold checking
- 🎯 Performance Budgets: Custom performance thresholds and budget monitoring
- 📚 Reference Resources: Built-in guidelines and best practices for web performance, accessibility, SEO, and security

🛠️ Requirements

- Node.js 22.0.0 or newer
- Chrome/Chromium browser (automatically managed by Lighthouse)
- VS Code, Cursor, Windsurf, Claude Desktop, or any other MCP client

🚀 Getting Started

Install the Lighthouse MCP server with your preferred client using one of the configurations below:

``json
{
"mcpServers": {
"lighthouse": {
"command": "npx",
"args": ["@danielsogl/lighthouse-mcp@latest"]
}
}
}
`

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If you need authenticated sessions, launch with a persistent Chrome profile and run headed:

`json
{
"mcpServers": {
"lighthouse": {
"command": "npx",
"args": [
"@danielsogl/lighthouse-mcp@latest",
"--profile-path",
"",
"--no-headless"
]
}
}
}
`

You can pass extra Chrome flags with --chrome-flag, for example --chrome-flag=--disable-gpu.
If the flag value starts with -- and matches a known option name, prefer --chrome-flag=... to avoid parsing it as a top-level option.
Profile mode disables Lighthouse's storage reset so cookies and local storage persist between runs.
If --user-data-dir points to a missing directory, it will be created and treated as a fresh profile.
Set --profile-path to the Profile Path shown in chrome://version (e.g. .../Default).
Note: Chrome's remote debugging requires a non-default user data directory, so reuse a dedicated profile directory instead of the system default.
You can also pass --user-data-dir + --profile-directory separately if you prefer.
Attaching with --chrome-port alone does not preserve storage; include a profile flag to keep sessions.

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Supported runtime flags for the MCP server:

- --profile-path : use the Profile Path from chrome://version (auto-derives user data dir + profile name)
- --user-data-dir : reuse a Chrome profile directory for persistent sessions
- --profile-directory : select a profile within the user data dir
- --chrome-flag or --chrome-flag=: pass through extra Chrome flags (repeatable)
- --chrome-port or --remote-debugging-port : attach to an existing Chrome instance launched with remote debugging enabled
- --headless: force headless mode
- --no-headless: force headed mode

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Run a real audit with a persistent profile (use an existing profile directory and log in once if needed):

`bash
npm run smoke:profile -- --url https://example.com \
--profile-path "" \
--no-headless
`

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Start Chrome with remote debugging enabled:

`bash
/path/to/GoogleChromeExecutable \
--remote-debugging-port=9222 \
--user-data-dir /path/to/chrome-profile
`

Replace /path/to/GoogleChromeExecutable with your platform's Chrome/Chromium binary path.

Then attach Lighthouse to that instance:

`bash
npm run smoke:profile -- --url https://example.com --chrome-port 9222
`

To preserve storage when attaching, pass the profile path so Lighthouse keeps cookies/local storage:

`bash
npm run smoke:profile -- --url https://example.com \
--chrome-port 9222 \
--profile-path ""
`

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![Install MCP Server](https://cursor.com/install-mcp?name=lighthouse&config=eyJjb21tYW5kIjoibnB4IC15IEBkYW5pZWxzb2dsL2xpZ2h0aG91c2UtbWNwQGxhdGVzdCJ9)

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🔧 Available Tools

The Lighthouse MCP server provides the following tools for comprehensive web analysis:

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| Tool | Description | Parameters |
| ------------------------- | ------------------------------------------- | ---------------------------------------------- |
| run_audit | Run a comprehensive Lighthouse audit | url, categories?, device?, throttling? |
| get_accessibility_score | Get accessibility score and recommendations | url, device?, includeDetails? |
| get_seo_analysis | Get SEO analysis and recommendations | url, device?, includeDetails? |
| check_pwa_readiness | Check Progressive Web App readiness | url, device?, includeDetails? |

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| Tool | Description | Parameters |
| -------------------------- | ----------------------------------- | ------------------------------------------------------ |
| get_performance_score | Get overall performance score | url, device? |
| get_core_web_vitals | Get Core Web Vitals metrics | url, device?, includeDetails?, threshold? |
| compare_mobile_desktop | Compare performance across devices | url, categories?, throttling?, includeDetails? |
| check_performance_budget | Check against performance budgets | url, device?, budget |
| get_lcp_opportunities | Find LCP optimization opportunities | url, device?, includeDetails?, threshold? |

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| Tool | Description | Parameters |
| ------------------------ | ----------------------------- | --------------------------------------------------- |
| find_unused_javascript | Find unused JavaScript code | url, device?, minBytes?, includeSourceMaps? |
| analyze_resources | Analyze all website resources | url, device?, resourceTypes?, minSize? |

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| Tool | Description | Parameters |
| -------------------- | ------------------------------------ | --------------------------- |
| get_security_audit | Perform comprehensive security audit | url, device?, checks? |

💬 Available Prompts

The Lighthouse MCP server includes reusable prompts that help LLMs provide structured analysis and recommendations:

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| Prompt | Description | Parameters |
| -------------------------- | ------------------------------------------------ | --------------------------------------------------------------- |
| analyze-audit-results | Analyze Lighthouse audit results | auditResults, focusArea? |
| compare-audits | Compare before/after audit results | beforeAudit, afterAudit, changesImplemented? |
| optimize-core-web-vitals | Get Core Web Vitals optimization recommendations | coreWebVitals, framework?, constraints? |
| optimize-resources | Get resource optimization recommendations | resourceAnalysis, loadingStrategy?, criticalUserJourneys? |

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The Lighthouse MCP server provides built-in reference resources with essential guidelines and best practices:

| Resource | Description | URI |
| ---------------------------- | ------------------------------------------------- | ----------------------------------------------------- |
| core-web-vitals-thresholds | Core Web Vitals performance thresholds | lighthouse://performance/core-web-vitals-thresholds |
| optimization-techniques | Performance optimization techniques and impact | lighthouse://performance/optimization-techniques |
| wcag-guidelines | WCAG 2.1 accessibility guidelines and issues | lighthouse://accessibility/wcag-guidelines |
| seo-best-practices | SEO best practices and optimization opportunities | lighthouse://seo/best-practices |
| security-best-practices | Web security best practices and vulnerabilities | lighthouse://security/best-practices |
| budget-guidelines | Performance budget recommendations by site type | lighthouse://performance/budget-guidelines |
| categories-scoring | Lighthouse audit categories and scoring methods | lighthouse://audits/categories-scoring |
| framework-guides | Framework-specific optimization guides | lighthouse://frameworks/optimization-guides |

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| Prompt | Description | Parameters |
| --------------------------- | --------------------------------------------------- | ------------------------------------------------------- |
| create-performance-plan | Generate comprehensive performance improvement plan | currentMetrics, targetGoals?, timeframe? |
| create-performance-budget | Create custom performance budget recommendations | currentMetrics, businessGoals?, userBase? |
| seo-recommendations | Generate SEO improvement recommendations | seoAudit, websiteType?, targetAudience? |
| accessibility-guide | Create accessibility improvement guide | accessibilityAudit, complianceLevel?, userGroups? |

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- auditResults: JSON audit results from Lighthouse tools
- focusArea: Specific category to focus on ("performance", "accessibility", "seo", "best-practices", "pwa")
- beforeAudit / afterAudit: Lighthouse audit results before and after changes
- changesImplemented: Description of changes made between audits
- currentMetrics: Current performance metrics from audits
- targetGoals: Specific performance targets or business goals
- timeframe: Timeline for implementing improvements
- framework: Frontend framework or technology stack
- constraints: Technical or business constraints
- websiteType: Type of website (e.g., e-commerce, blog, corporate)
- targetAudience: Target audience or market information
- complianceLevel: WCAG compliance level ("AA" or "AAA")
- userGroups: Specific user groups to consider for accessibility

📋 Parameter Details

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- url (required): The website URL to analyze
- device: Target device ("desktop" or "mobile", default: "desktop")
- includeDetails: Include detailed audit information (default: false)
- throttling: Enable network/CPU throttling (default: false)

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- categories: Lighthouse categories to audit (["performance", "accessibility", "best-practices", "seo", "pwa"])
- threshold: Custom thresholds for metrics (e.g., {"lcp": 2.5, "fid": 100, "cls": 0.1})
- budget: Performance budget limits (e.g., {"performanceScore": 90, "largestContentfulPaint": 2500})
- resourceTypes: Resource types to analyze (["images", "javascript", "css", "fonts", "other"])
- minBytes: Minimum file size threshold for analysis (default: 2048)
- checks: Security checks to perform (["https", "mixed-content", "csp", "hsts", "vulnerabilities"])

💡 Usage Examples

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`javascript
// Get overall performance score
{
"tool": "get_performance_score",
"arguments": {
"url": "https://example.com",
"device": "mobile"
}
}
`

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`javascript
// Check Core Web Vitals with custom thresholds
{
"tool": "get_core_web_vitals",
"arguments": {
"url": "https://example.com",
"device": "mobile",
"includeDetails": true,
"threshold": {
"lcp": 2.5,
"fid": 100,
"cls": 0.1
}
}
}
`

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`javascript
// Comprehensive security audit
{
"tool": "get_security_audit",
"arguments": {
"url": "https://example.com",
"checks": ["https", "csp", "hsts"]
}
}
`

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`javascript
// Find optimization opportunities
{
"tool": "analyze_resources",
"arguments": {
"url": "https://example.com",
"resourceTypes": ["images", "javascript"],
"minSize": 1024
}
}
`

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Access built-in guidelines and best practices:

`javascript
// Get Core Web Vitals thresholds
{
"resource": {
"uri": "lighthouse://performance/core-web-vitals-thresholds"
}
}

// Access WCAG accessibility guidelines
{
"resource": {
"uri": "lighthouse://accessibility/wcag-guidelines"
}
}

// Get framework-specific optimization guides
{
"resource": {
"uri": "lighthouse://frameworks/optimization-guides"
}
}
`

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`javascript
// Analyze audit results with focused recommendations
{
"prompt": "analyze-audit-results",
"arguments": {
"auditResults": "{...lighthouse audit json...}",
"focusArea": "performance"
}
}

// Create a performance improvement plan
{
"prompt": "create-performance-plan",
"arguments": {
"currentMetrics": "{...current performance metrics...}",
"targetGoals": "Achieve 90+ performance score and sub-2s LCP",
"timeframe": "3 months"
}
}

// Compare before/after audit results
{
"prompt": "compare-audits",
"arguments": {
"beforeAudit": "{...before audit results...}",
"afterAudit": "{...after audit results...}",
"changesImplemented": "Implemented lazy loading and image optimization"
}
}
``

🎯 Use Cases

- Performance Monitoring: Automated performance tracking and Core Web Vitals monitoring
- Accessibility Compliance: WCAG 2.1 compliance checking and remediation guidance
- SEO Optimization: Technical SEO audits and search engine optimization recommendations
- Security Assessment: Vulnerability scanning and security best practice validation
- Resource Optimization: Bundle analysis and optimization opportunity identification
- Performance Budgets: Automated performance budget monitoring and alerting
- CI/CD Integration: Automated quality gates and performance regression detection

🏗️ Architecture

The server is built using:

- Model Context Protocol SDK: For MCP server implementation
- Google Lighthouse: For web performance auditing
- Chrome Launcher: For browser automation
- TypeScript: For type safety and better developer experience
- Zod: For runtime schema validation

🤝 Contributing

Contributions are welcome! Please read our Contributing Guide for details on:

- Code style and standards
- Testing requirements
- Pull request process
- Development setup

📜 License

This project is licensed under the MIT License - see the LICENSE file for details.

🔒 Security

For security issues, please see our Security Policy.

📞 Support

- 🐛 Bug Reports: GitHub Issues
- 💬 Discussions: GitHub Discussions
- 📧 Email: security@codingrules.ai

🙏 Acknowledgments

- Google Lighthouse team for the excellent auditing engine
- Anthropic for the Model Context Protocol specification
- The open source community for continuous inspiration and contributions

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Built with ❤️ by Daniel Sogl