10 min readTutorial

Website Audit API for Developers: Automate SEO and Performance Checks

A client asks "how's my website doing?" and you spend 30 minutes in PageSpeed Insights. What if one API call gave you everything?

Why Developers Need a Website Audit API

Manual website audits don't scale. Whether you're building an SEO tool, a lead qualification system, an agency dashboard, or a monitoring service — you need programmatic access to website performance data.

The question isn't whether to use an API. It's which one.

What a Good Website Audit API Returns

A useful audit API covers five categories:

Performance

Load time, speed score (0-100), page weight, request count, TTFB

SEO

Title tag, meta description, H1 tags, alt text coverage, canonical URLs, sitemap/robots.txt, structured data

Mobile

Responsiveness score, viewport config, touch target sizing, font readability

Security

HTTPS status, SSL validity, mixed content, HSTS/CSP/X-Frame-Options headers

Tech Stack

CMS detection (WordPress/Shopify/Wix), analytics, chat widgets, forms, social links

Current Options Compared

Google Lighthouse / PageSpeed Insights API

Free and well-established. Great for performance metrics.

  • Strength: free, comprehensive performance data, integrates with CI/CD
  • Weakness: slow (10-30 seconds per audit), focused on performance not business intelligence, rate-limited
  • Verdict: Great for one-off checks. Doesn't scale for bulk auditing or lead scoring.

Ahrefs / SEMrush APIs

Enterprise-grade SEO data. Comprehensive backlink and keyword analysis.

  • Strength: deep SEO data, backlink profiles, keyword tracking
  • Weakness: expensive ($99-$449/month minimum), designed for SEO professionals, overkill for simple site scoring
  • Verdict: Unbeatable for SEO professionals. Overkill if you just need a quick site health check.

Rebirth API — Website Audit Endpoint

$0.10 per audit. Returns speed, SEO, mobile, and competitor comparison in one call.

  • Strength: one call gets everything, same API key as business lookup and lead enrichment, no monthly minimum
  • Weakness: newer platform, no backlink data (use Ahrefs for that)
  • Verdict: Best for developers who need actionable website scores without enterprise pricing.
Use CaseLighthouseAhrefs/SEMrushRebirth API
One-off performance checkBestOverkillOverkill
Bulk auditing 100+ sitesToo slowPossibleBest
Lead qualification scoringNo biz contextNot designed for thisBest
Deep SEO / backlinksNoBestNo
CI/CD performance gatesBestNoPossible
Client reporting dashboardManual exportPossibleBest

Building a Lead Scoring System with Website Audits

Here's the real unlock: combine website audit data with business lookup to automatically score and qualify leads.

Python
import requests

API_KEY = "rb_live_your_key"
HEADERS = {"Authorization": f"Bearer {API_KEY}", "Content-Type": "application/json"}

def score_lead(business_name: str, city: str) -> dict:
    """Look up a business, audit their website, return a lead score."""

    # Step 1: Find the business
    biz = requests.post("https://rebirthapi.com/api/v1/business-lookup",
        headers=HEADERS,
        json={"query": business_name, "city": city, "limit": 1}
    ).json()

    if not biz.get("results"):
        return {"score": 0, "reason": "Business not found"}

    business = biz["results"][0]
    website = business.get("website")

    if not website:
        return {"score": 80, "business": business,
                "reason": "No website at all — hot lead for web services"}

    # Step 2: Audit their website
    audit = requests.post("https://rebirthapi.com/api/v1/website-audit",
        headers=HEADERS,
        json={"url": website}
    ).json()

    # Step 3: Score based on pain points
    score = 0
    reasons = []

    if audit["scores"]["speed"] < 50:
        score += 30
        reasons.append(f"Slow site (speed score: {audit['scores']['speed']})")

    if audit["scores"]["seo"] < 60:
        score += 25
        reasons.append(f"Poor SEO (score: {audit['scores']['seo']})")

    if not audit["scores"]["mobile"] or audit["scores"]["mobile"] < 70:
        score += 25
        reasons.append("Not mobile-friendly")

    if business.get("rating", 5) < 4.0:
        score += 20
        reasons.append(f"Low rating ({business['rating']} stars)")

    return {
        "score": min(score, 100),
        "priority": "hot" if score >= 50 else "warm" if score >= 25 else "cold",
        "business": business,
        "website_scores": audit["scores"],
        "reasons": reasons
    }

# Example usage
lead = score_lead("Joe's Auto Shop", "Houston, TX")
print(f"Lead score: {lead['score']} ({lead['priority']})")
print(f"Reasons: {', '.join(lead['reasons'])}")

Two API calls. One API key. An automated lead scoring pipeline that would take an hour to do manually.

Bulk Auditing for Agencies

JavaScript
async function auditClientWebsites(websites) {
  const results = [];

  // Process in batches of 5 to respect rate limits
  for (let i = 0; i < websites.length; i += 5) {
    const batch = websites.slice(i, i + 5);
    const audits = await Promise.all(
      batch.map(url =>
        fetch('https://rebirthapi.com/api/v1/website-audit', {
          method: 'POST',
          headers: {
            'Authorization': 'Bearer rb_live_your_key',
            'Content-Type': 'application/json'
          },
          body: JSON.stringify({ url })
        }).then(r => r.json())
      )
    );
    results.push(...audits);
  }

  // Sort by worst-performing first — these need attention
  return results.sort((a, b) => a.scores.overall - b.scores.overall);
}

FAQ

How fast is a website audit API call?

Lighthouse takes 10-30 seconds. Most API-based audits complete in 2-5 seconds because they cache and optimize the analysis pipeline.

Can I audit competitor websites?

Yes. Website audits are based on publicly available information. You can audit any publicly accessible website.

How is this different from running Lighthouse myself?

Lighthouse gives you raw performance metrics. A website audit API adds business context: SEO scoring, competitor comparison, feature detection, and actionable recommendations. Plus it runs in seconds, not 30.

What's the best way to use audit data for sales?

Combine it with business lookup data. Find businesses in a category, audit their websites, and sort by the ones with the worst scores. Those are your hottest leads.

Try the API

Business Lookup is live now. Website Audit is coming soon. Get your free API key to be first in line.

Get Free API Key