Dependency Analyzer

Analyze all external resources and dependencies loaded by any webpage. Discover scripts, stylesheets, images, fonts, and iframes to understand a site's external dependencies and third-party integrations.

API ReferenceCopy Anchor Link

GET /analyzeCopy Anchor Link

Analyze all external dependencies of a webpage by providing its URL.

Example RequestCopy Anchor Link

curl "https://your-worker.workers.dev/analyze?url=https://www.cloudflare.com"

Response StructureCopy Anchor Link

success boolean

Indicates if the request was successful

data object

The analyzed dependencies from the webpage

data.scripts string[]

Array of unique absolute URLs of JavaScript files loaded via <script src="...">. Includes all external scripts referenced in the HTML.

data.stylesheets string[]

Array of unique absolute URLs of CSS files loaded via <link rel="stylesheet" href="...">. Includes all external stylesheets.

data.images string[]

Array of unique absolute URLs of images. Extracts from both <img src="..."> and <source src="..."> tags.

data.fonts string[]

Array of unique absolute URLs of font files. Extracts from: - <link rel="preload" as="font" href="..."> - CSS url() declarations for .woff, .woff2, .ttf, .otf, and .eot files

data.iframes string[]

Array of unique absolute URLs of embedded iframes via <iframe src="...">. Useful for identifying third-party embeds.

Example ResponseCopy Anchor Link

{
  "success": true,
  "data": {
    "scripts": [
      "https://www.cloudflare.com/js/main.bundle.js",
      "https://www.googletagmanager.com/gtag/js?id=UA-12345678",
      "https://static.cloudflareinsights.com/beacon.min.js",
      "https://ajax.cloudflare.com/cdn-cgi/scripts/analytics.js"
    ],
    "stylesheets": [
      "https://www.cloudflare.com/css/main.css",
      "https://www.cloudflare.com/css/responsive.css",
      "https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700"
    ],
    "images": [
      "https://www.cloudflare.com/img/logo.svg",
      "https://www.cloudflare.com/img/hero-background.jpg",
      "https://imagedelivery.net/abc123/hero.png/public"
    ],
    "fonts": [
      "https://www.cloudflare.com/fonts/inter-regular.woff2",
      "https://www.cloudflare.com/fonts/inter-bold.woff2",
      "https://fonts.gstatic.com/s/inter/v12/UcC73FwrK3iLTeHuS_fvQtMwCp50KnMa1ZL7.woff2"
    ],
    "iframes": [
      "https://www.youtube.com/embed/dQw4w9WgXcQ",
      "https://player.vimeo.com/video/123456789"
    ]
  }
}

Error ResponsesCopy Anchor Link

Invalid URLCopy Anchor Link

{
  "success": false,
  "error": "Missing or invalid query parameter: url",
  "code": "INVALID_URL"
}

Fetch ErrorCopy Anchor Link

{
  "success": false,
  "error": "HTTP 404",
  "code": "FETCH_ERROR"
}

Technical DetailsCopy Anchor Link

• Built with Hono framework
• Runs on Cloudflare Workers
• Regex-based HTML parsing for fast extraction
• Automatically resolves relative URLs to absolute URLs
• Deduplicates all resource URLs
• Extracts fonts from both link tags and CSS url() declarations

Extraction DetailsCopy Anchor Link

ScriptsCopy Anchor Link

• Extracted from <script src="..."> tags
• Includes inline and external JavaScript references
• Does not include inline script content

StylesheetsCopy Anchor Link

• Extracted from <link rel="stylesheet" href="...">
• Includes both standard and alternate stylesheets
• Matches various ordering of rel and href attributes

ImagesCopy Anchor Link

• Extracted from <img src="..."> tags
• Also extracts from <source src="..."> for responsive images
• All formats supported (jpg, png, svg, gif, webp, etc.)

FontsCopy Anchor Link

• Extracted from <link rel="preload" as="font"> or <link rel="stylesheet" as="font">
• Also extracts from CSS url() declarations matching font extensions:
  • .woff and .woff2 (Web Open Font Format)
  • .ttf (TrueType Font)
  • .otf (OpenType Font)
  • .eot (Embedded OpenType)

IframesCopy Anchor Link

• Extracted from <iframe src="..."> tags
• Useful for identifying embeds from YouTube, Vimeo, Google Maps, etc.
• Includes both same-origin and cross-origin iframes

NotesCopy Anchor Link

• All resource URLs are deduplicated across each category
• Relative URLs are resolved using the base URL of the page
• The tool fetches and analyzes the initial HTML only (does not execute JavaScript)
• Resources loaded dynamically after page load are not captured

Use CasesCopy Anchor Link

• Dependency Audits: Identify all third-party dependencies and external resources
• Performance Analysis: Discover resource-heavy pages loading too many external files
• Security Reviews: Find all external scripts and potential security risks
• Privacy Compliance: Identify third-party trackers and analytics scripts
• License Compliance: Discover all fonts and resources that may require licensing
• CDN Optimization: Identify candidates for CDN migration or consolidation
• Competitive Analysis: Understand what services and tools competitors use

LimitationsCopy Anchor Link

• Static HTML only; assets loaded dynamically by JavaScript are not detected
• HTML body is capped before parsing
• Fetch timeout on slow or unreachable origins
• Single URL per request; no site-wide crawling

Use in your projectCopy Anchor Link

import { FETCH_TIMEOUT_MS, MAX_HTML_BYTES } from "../constants/defaults";export async function fetchHtml(url: string): Promise<string> {  const controller = new AbortController();  const timeoutId = setTimeout(() => controller.abort(), FETCH_TIMEOUT_MS);  try {    const res = await fetch(url, {      method: "GET",      signal: controller.signal,      headers: {        "User-Agent": "Cloudflare-Experiments-DependencyAnalyzer/1.0",        Accept: "text/html",      },    });    clearTimeout(timeoutId);    if (!res.ok) throw new Error(`HTTP ${res.status}`);    const text = await res.text();    return text.length > MAX_HTML_BYTES ? text.slice(0, MAX_HTML_BYTES) : text;  } finally {    clearTimeout(timeoutId);  }}

DeploymentCopy Anchor Link

curl "https://your-worker.workers.dev/analyze?url=https://example.com"

Local DevelopmentCopy Anchor Link

cd apps/experiments/dependency-analyzer
npm install
npm run dev

Test locally:

curl "http://localhost:8787/analyze?url=https://example.com"

Cloudflare Features UsedCopy Anchor Link

• Workers - Edge compute runtime
• Fetch API - Remote HTML retrieval and parsing