How to Build a Website SEO Audit Tool in JavaScript (Free APIs)

curl -X POST https://api.frostbyte.world/api/keys/create

const API_KEY = process.env.FROSTBYTE_KEY || 'your-key-here';
const BASE = 'https://api.frostbyte.world';

async function api(path) {
  const res = await fetch(`${BASE}${path}`, {
    headers: { 'x-api-key': API_KEY }
  });
  return res.json();
}

async function auditSEO(url) {
  const domain = new URL(url).hostname;
  console.log(`\n🔍 SEO Audit: ${url}\n${'='.repeat(50)}`);

  // 1. Scrape the page for meta tags and structure
  console.log('\n📄 Page Analysis...');
  const page = await api(`/api/scraper/scrape?url=${encodeURIComponent(url)}`);

  if (page.metadata) {
    const m = page.metadata;
    console.log(`  Title: ${m.title || '❌ MISSING'}`);
    console.log(`  Title length: ${(m.title || '').length}/60 ${(m.title || '').length > 60 ? '⚠️ Too long' : '✅'}`);
    console.log(`  Description: ${m.description ? m.description.slice(0, 80) + '...' : '❌ MISSING'}`);
    console.log(`  Desc length: ${(m.description || '').length}/160 ${(m.description || '').length > 160 ? '⚠️ Too long' : '✅'}`);
    console.log(`  Canonical: ${m.canonical || '⚠️ Not set'}`);
    console.log(`  OG Image: ${m.ogImage ? '✅' : '❌ MISSING'}`);
    console.log(`  Robots: ${m.robots || 'Not set (defaults to index)'}`);
  }

  // Check headings structure
  if (page.content) {
    const h1s = (page.content.match(/<h1[^>]*>/gi) || []).length;
    const h2s = (page.content.match(/<h2[^>]*>/gi) || []).length;
    console.log(`\n  Headings:`);
    console.log(`    H1 tags: ${h1s} ${h1s === 1 ? '✅' : h1s === 0 ? '❌ Missing H1' : '⚠️ Multiple H1s'}`);
    console.log(`    H2 tags: ${h2s} ${h2s > 0 ? '✅' : '⚠️ No H2 tags'}`);
  }

  // Count links
  if (page.links) {
    const internal = page.links.filter(l => l.includes(domain)).length;
    const external = page.links.length - internal;
    console.log(`\n  Links: ${page.links.length} total (${internal} internal, ${external} external)`);
  }

  // 2. Check DNS records
  console.log('\n🌐 DNS & Hosting...');
  const dns = await api(`/api/dns/lookup?domain=${domain}`);

  if (dns.records) {
    const aRecords = dns.records.filter(r => r.type === 'A');
    const cnameRecords = dns.records.filter(r => r.type === 'CNAME');
    const mxRecords = dns.records.filter(r => r.type === 'MX');
    console.log(`  A Records: ${aRecords.map(r => r.value).join(', ') || 'None'}`);
    console.log(`  CNAME: ${cnameRecords.map(r => r.value).join(', ') || 'None'}`);
    console.log(`  MX Records: ${mxRecords.length > 0 ? '✅ Email configured' : '⚠️ No MX records'}`);
  }

  // 3. Check hosting IP info
  if (dns.records) {
    const ip = dns.records.find(r => r.type === 'A')?.value;
    if (ip) {
      const geo = await api(`/api/ip/geo?ip=${ip}`);
      if (geo.country) {
        console.log(`  Server: ${geo.city || '?'}, ${geo.country} (${geo.isp || geo.org || '?'})`);
        console.log(`  Hosting: ${geo.org || geo.isp || 'Unknown'}`);
      }
    }
  }

  // 4. Take a screenshot
  console.log('\n📸 Screenshot...');
  const screenshot = await api(`/api/screenshot/take?url=${encodeURIComponent(url)}&width=1280&height=800`);
  if (screenshot.url) {
    console.log(`  Saved: ${screenshot.url}`);
  }

  // Generate score
  console.log(`\n${'='.repeat(50)}`);
  console.log('📊 Quick Score:');
  let score = 0;
  let total = 0;

  const checks = [
    [!!page.metadata?.title, 'Has title tag'],
    [(page.metadata?.title || '').length <= 60, 'Title under 60 chars'],
    [!!page.metadata?.description, 'Has meta description'],
    [(page.metadata?.description || '').length <= 160, 'Description under 160 chars'],
    [!!page.metadata?.ogImage, 'Has OG image'],
    [!!page.metadata?.canonical, 'Has canonical URL'],
    [(page.content?.match(/<h1[^>]*>/gi) || []).length === 1, 'Exactly one H1'],
    [(page.content?.match(/<h2[^>]*>/gi) || []).length > 0, 'Has H2 headings'],
    [dns.records?.some(r => r.type === 'MX'), 'MX records configured'],
    [!!screenshot?.url, 'Page renders successfully'],
  ];

  checks.forEach(([pass, label]) => {
    total++;
    if (pass) score++;
    console.log(`  ${pass ? '✅' : '❌'} ${label}`);
  });

  console.log(`\n  Score: ${score}/${total} (${Math.round(score/total*100)}%)`);
}

// Run it
const url = process.argv[2] || 'https://example.com';
auditSEO(url).catch(console.error);

export FROSTBYTE_KEY="your-api-key"
node seo-audit.js https://dev.to

🔍 SEO Audit: https://dev.to
==================================================

📄 Page Analysis...
  Title: DEV Community
  Title length: 13/60 ✅
  Description: A constructive and inclusive social network for software develo...
  Desc length: 95/160 ✅
  Canonical: https://dev.to/
  OG Image: ✅
  Robots: Not set (defaults to index)

  Headings:
    H1 tags: 1 ✅
    H2 tags: 12 ✅

  Links: 87 total (64 internal, 23 external)

🌐 DNS & Hosting...
  A Records: 151.101.1.38, 151.101.65.38
  CNAME: None
  MX Records: ✅ Email configured
  Server: San Francisco, US (Fastly)
  Hosting: Fastly, Inc

📸 Screenshot...
  Saved: https://api.frostbyte.world/screenshots/dev.to-1709...png

==================================================
📊 Quick Score:
  ✅ Has title tag
  ✅ Title under 60 chars
  ✅ Has meta description
  ✅ Description under 160 chars
  ✅ Has OG image
  ✅ Has canonical URL
  ✅ Exactly one H1
  ✅ Has H2 headings
  ✅ MX records configured
  ✅ Page renders successfully

  Score: 10/10 (100%)

const start = Date.now();
const res = await fetch(url);
const loadTime = Date.now() - start;
console.log(`  Load time: ${loadTime}ms ${loadTime < 1000 ? '✅' : '⚠️ Slow'}`);

const pages = [
  'https://example.com',
  'https://example.com/about',
  'https://example.com/blog',
];

for (const page of pages) {
  await auditSEO(page);
}

const results = {
  url,
  timestamp: new Date().toISOString(),
  score: `${score}/${total}`,
  checks: checks.map(([pass, label]) => ({ pass, label })),
};
require('fs').writeFileSync('audit.json', JSON.stringify(results, null, 2));