Website Favicon and App Icon Checker

// api/fetchFavicon.js (extract)
const cheerio = require('cheerio');

module.exports = async (req, res) => {
  const { url } = req.query;
  const targetUrl = new URL(url);
  const origin = targetUrl.origin;

  const response = await fetch(targetUrl.href, {
    headers: {
      'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) IconChecker/1.0'
    }
  });

  const html = await response.text();
  const $ = cheerio.load(html);
  const icons = [];

  // Query DOM for standard and mobile icon declarations
  $('link[rel="icon"], link[rel="shortcut icon"], link[rel="apple-touch-icon"], link[rel="mask-icon"]').each((_, el) => {
    const href = $(el).attr('href');
    const rel = $(el).attr('rel');
    const sizes = $(el).attr('sizes') || 'any';
    const type = $(el).attr('type') || '';

    if (href) {
      try {
        const absoluteUrl = new URL(href, targetUrl.href).href;
        icons.push({ url: absoluteUrl, rel, sizes, type });
      } catch (e) {
        // Ignore invalid URL strings
      }
    }
  });

  // Always check default root fallback if no favicon was discovered in HTML
  if (!icons.some(i => i.rel.includes('icon'))) {
    icons.push({ url: `${origin}/favicon.ico`, rel: 'icon (default fallback)', sizes: '32x32', type: 'image/x-icon' });
  }

  // ...
};

async function parseManifestIcons(manifestUrl, icons) {
  try {
    const res = await fetch(manifestUrl);
    if (!res.ok) return;
    const manifest = await res.json();

    if (Array.isArray(manifest.icons)) {
      for (const icon of manifest.icons) {
        icons.push({
          url: new URL(icon.src, manifestUrl).href,
          rel: `manifest (${icon.purpose || 'any'})`,
          sizes: icon.sizes || 'any',
          type: icon.type || 'image/png'
        });
      }
    }
  } catch (err) {
    // Graceful fallback if manifest is inaccessible
  }
}