BuiltWith API

builtwith-api is a utility wrapper for the BuiltWith API suite. Find out what any website is built with!

Available as a library, CLI, and MCP server.

Installation

npm install builtwith-api

Requires Node.js >= 18 (uses native fetch).

Breaking Changes in v3

• ESM-only - no more CommonJS/require() support
• Named export - import { createClient } from 'builtwith-api' (not default/require)
• Zod validation - invalid inputs throw ZodError instead of manual error messages
• Typed responses - methods return typed response objects (when using JSON format)

Features

Response Formats

• JSON support
• XML support
• CSV support
• TSV support (lists, relationships)
• TXT support (lists only)

APIs

| Method | Description | |--------|-------------| | free | Free technology summary | | domain | Full domain technology lookup | | lists | Sites using a technology | | relationships | Related domains | | keywords | Domain keyword extraction | | trends | Technology adoption trends | | companyToUrl | Company name to domains | | domainLive | Live domain detection | | trust | Trust & fraud signals | | tags | IP & attribute lookups | | recommendations | Technology suggestions | | redirects | Redirect chain history | | product | E-commerce product search |

Library Usage

import { createClient } from 'builtwith-api'

// Initialize with your API key
const builtwith = createClient(process.env.YOUR_BUILTWITH_API_KEY, {
  responseFormat: 'json' // 'json' 'xml' 'csv' 'tsv' 'txt' (txt only for lists API)
})

const url = 'facebook.com'

// Free lookup - quick summary
await builtwith.free(url)

// Full domain analysis
await builtwith.domain(url, {
  // This will hide technology description, link, tag and category fields
  hideAll: false,
  // This will hide technology description and link fields (but keep tag and categories)
  hideDescriptionAndLinks: false,
  // This will only return technologies we consider to be live
  onlyLiveTechnologies: true,
  // No meta data (like address, names etc..) will be returned. Improves performance.
  noMetaData: true,
  // No attributes data will be returned
  noAttributeData: true,
  // No personally identifiable information will be returned
  noPII: true,
  // Filter by first detected date range (e.g. '2020-01-01-2024-12-31')
  firstDetectedRange: undefined,
  // Filter by last detected date range
  lastDetectedRange: undefined
})

// List sites using a technology
const technology = 'Shopify'
// The name of a technology. Spaces automatically replaced with dashes (-).
await builtwith.lists(technology, {
  // Brings back meta data with the results, which includes names, titles, social links, addresses, emails, telephone numbers, traffic ranks etc.
  includeMetaData: true,
  // Gets the next page of results - use the exact value from NextOffset in response. If the value of NextOffset is END there are no more results.
  offset: 'oQEwEnH2FJuIzeXOEk2T',
  // Gets live sites using the technology since a certain time, accepts dates and queries i.e. 30 Days Ago or Last January for example.
  since: '2016-01-20'
})

// Find related domains
await builtwith.relationships(url)

// Multi-domain keyword lookup (up to 16 domains)
const urls = ['hotelscombined.com', 'builtwith.com']
await builtwith.keywords(urls)

// Technology trends over time
await builtwith.trends(technology, {
  // Totals will be the closest to this date - providing the ability to get historical totals
  date: '2016-01-20'
})

// Find a company's website
const companyName = 'Shell'
await builtwith.companyToUrl(companyName, {
  // Bring back domains in order of priority - the first result is generally the one we think the website is
  amount: 1,
  // Set the priority extension - if you know the country of the company supply the most likely TLD. i.e. for United Kingdom use 'uk'
  tld: 'com'
})

// Live domain detection
await builtwith.domainLive(url)

// Trust & fraud detection
await builtwith.trust(url, {
  // If the words specified here are in the HTML of the website the result will have Stopwords set to true for LIVE lookups.
  words: 'medicine,masks',
  // Performs a live lookup of the website in question. This slows down the response. A result with a status of 'needLive' requires the LIVE option to determine if the website is suspect or not.
  live: false
})

// Get domains related to IPs and site attributes. Use 'IP-1.2.3.4' format for IP lookups.
await builtwith.tags(url)

// Get technology recommendations for a domain
await builtwith.recommendations(url)

// Get live and historical redirect data for a domain
await builtwith.redirects(url)

// Search for e-commerce sites selling specific products
await builtwith.product('shoes')

CLI

The CLI wraps all 13 API methods. No extra dependencies beyond the package itself.

builtwith <command> <primary-arg> [--flag value ...]

Authentication

Pass your API key via --api-key or the BUILTWITH_API_KEY environment variable:

# Flag
builtwith free example.com --api-key YOUR_KEY

# Environment variable
export BUILTWITH_API_KEY=YOUR_KEY
builtwith free example.com

Examples

builtwith free example.com
builtwith domain example.com --hideAll --onlyLiveTechnologies
builtwith domain "example.com,other.com"
builtwith lists Shopify --since 2024-01-01
builtwith companyToUrl "Acme Corp" --amount 5 --tld com
builtwith trust example.com --words "shop,buy" --live
builtwith trends React --date 2024-06-01

Use --help for full usage or builtwith <command> --help for command-specific options:

builtwith --help
builtwith domain --help
builtwith --version

MCP Server

The package includes an MCP server that exposes all 13 API methods as tools for LLM clients (Claude Desktop, etc.).

Claude Desktop Configuration

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "builtwith": {
      "command": "npx",
      "args": ["-y", "-p", "builtwith-api", "builtwith-mcp"],
      "env": {
        "BUILTWITH_API_KEY": "YOUR_KEY"
      }
    }
  }
}

Or passing the key directly:

{
  "mcpServers": {
    "builtwith": {
      "command": "npx",
      "args": ["-y", "-p", "builtwith-api", "builtwith-mcp", "--api-key", "YOUR_KEY"]
    }
  }
}

Tools

All tools are prefixed with builtwith_:

| Tool | Description | |------|-------------| | builtwith_free | Free technology profile for a domain | | builtwith_domain | Detailed technology profile (supports comma-separated multi-domain) | | builtwith_lists | List domains using a specific technology | | builtwith_relationships | Find related domains via shared identifiers | | builtwith_keywords | Get keywords for domains | | builtwith_trends | Technology adoption trends | | builtwith_companyToUrl | Find domains for a company name | | builtwith_domainLive | Live technology lookup | | builtwith_trust | Trust/verification score | | builtwith_tags | Tracking/analytics tags | | builtwith_recommendations | Technology recommendations | | builtwith_redirects | Redirect chain history | | builtwith_product | E-commerce product search |

Testing with MCP Inspector

npx @modelcontextprotocol/inspector node dist/mcp.js

Learn More

Check out the full API docs at api.builtwith.com

For LLM-friendly API documentation, see api.builtwith.com/llms.txt