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🚀 Now in Public Beta · Updated
The free SEO audit API.
One call. 82 checks per URL.
A free SEO audit API for developers — score any URL across on-page SEO, performance, accessibility, and AI readability in seconds. Sits alongside Ahrefs and Moz; built to live in your code, CI/CD, and AI agents. Free tier. No card needed.
One API. Many roles.
Use SEO Score API as your SEO ranking API, SEO checker API, SEO audit API, SEO monitor API, or SEO report API — same key, same JSON, all 82 checks per call.
What does SEO Score API check?
82 checks across SEO, AI readability, SXO, AEO, and AIO in every paid audit
SEO Score API checks any URL across seven areas. Each check returns pass, warning, or fail. You get a 0-100 score and a letter grade. Most pages finish in two seconds. It works on JavaScript sites and Cloudflare pages. The JSON format plugs into any tool.
📝
Meta & Content
Title, description, headings, word count, and readability. Plus image alt text and link analysis.
⚙️
Technical SEO
HTTPS, SSL, response time, and canonical tags. Also checks robots.txt, sitemap.xml, and structured data.
📱
Social & Open Graph
Validates OG tags, Twitter Cards, and favicons. Ensures links look great when shared.
⚡
Performance
Measures HTML size, DOM complexity, and compression. Flags render-blocking resources.
♿
Accessibility
Checks lang attribute, image alt coverage, and ARIA landmarks.
🤖
AI Readability Score
Can GPTBot and ClaudeBot parse your page? Scores crawl access, structure, and extractability.
🌐
GEO Audit
Measure how visible your content is to AI search engines. 26 checks across crawl access, structured data, content structure, entity clarity, and freshness signals.
🎯
Priority Fixes
Ranked, actionable recommendations. Not just scores — clear guidance on what to fix first.
📈
Historical Tracking
Every audit on paid plans includes the score delta vs. the last run. Pull full timeseries for any URL via GET /history for trend reports and SLA dashboards.
Which 82 checks does the API run?
Each check returns a status, a score, and an actionable fix
The engine runs 28 SEO checks, 26 AI Readability checks, and 28 checks across SXO, AEO and AIO scoring. Every category returned in one API call.
📝 Meta & Content (8 checks)
- ✓ Title tag length
- ✓ Meta description
- ✓ H1 tag count
- ✓ Heading hierarchy
- ✓ Content length
- ✓ Readability score
- ✓ Image alt text
- ✓ Link ratio
⚙️ Technical SEO (10 checks)
- ✓ Response time
- ✓ HTTPS
- ✓ SSL certificate
- ✓ Status code
- ✓ Canonical tag
- ✓ Viewport meta
- ✓ Robots meta
- ✓ Structured data
- ✓ robots.txt
- ✓ sitemap.xml
📱 Social & OG (3 checks)
- ✓ Open Graph tags
- ✓ Twitter Card
- ✓ Favicon
♿ Accessibility (3 checks)
- ✓ Lang attribute
- ✓ Image alt text
- ✓ ARIA landmarks
⚡ Performance (4 checks)
- ✓ HTML size
- ✓ DOM complexity
- ✓ Compression
- ✓ Render-blocking
🤖 AI Readability (26 checks)
- ✓ SSR content detected
- ✓ AI bot allow-list
- ✓ llms.txt present
- ✓ JSON-LD schema types
- ✓ Semantic HTML ratio
- ✓ Heading hierarchy depth
- ✓ Lists & tables count
- ✓ Answer-first sections
- ✓ Chunk-friendly structure
- ✓ Fact density
- ✓ Author E-E-A-T signals
- ✓ Source citations
- ✓ Freshness & date_modified
- ✓ Internal-link graph
- ✓ Reading-ease score
- … and 11 more
🎯 SXO Scoring (part of 28)
- ✓ Mobile viewport
- ✓ Click target sizing
- ✓ Above-the-fold weight
- ✓ Breadcrumb navigation
- ✓ Visual hierarchy
💡 AEO Scoring
- ✓ FAQPage / HowTo schema
- ✓ Question headings
- ✓ Direct-answer paragraphs
- ✓ Featured-snippet readiness
🧠 AIO Scoring
- ✓ LLM ingestion signals
- ✓ Citation worthiness
- ✓ Entity clarity
- ✓ Knowledge-graph alignment
How do you integrate SEO Score API?
Add SEO scoring to any app in minutes. Use Python, JavaScript, cURL, or any HTTP client. Pass a URL. Get a full report. The response includes the score, grade, checks, and fixes. Use the X-API-Key header for auth.
import requests
response = requests.get(
"https://seoscoreapi.com/audit",
params={"url": "https://stripe.com"},
headers={"X-API-Key": "ssa_your_key_here"}
)
data = response.json()
print(f"Score: {data['score']}/100 ({data['grade']})")
print(f"Top fix: {data['priorities'][0]['issue']}")
# Output:
# Score: 74/100 (B)
# Top fix: 30 images missing alt text
How does SEO Score API compare to Lighthouse, Ahrefs, and ChatSEO?
Honest side-by-side. Pick the right tool for the job.
See all comparisons or browse alternatives by use case.
How much does SEO Score API cost?
Start free. Scale when you need to.
Free
$0
forever
- 2 audits / day
- 54 core checks
- 2 requests / minute
- No historical tracking
Starter
$5
per month
- 200 audits / month
- All 82 checks
- 10 requests / minute
- 🔍 SXO, AEO & AIO scores
- ♿ 5 ADA audits / month
- 📊 Score monitoring (5 URLs)
- 📦 Batch audits
- 📈 Historical tracking & trends (30 days)
- Email support
Basic
$15
per month
- 1,000 audits / month
- All 82 checks
- 30 requests / minute
- 🔍 SXO, AEO & AIO scores
- 1 GEO audit / month
- ♿ 20 ADA audits / month
- 📊 Score monitoring (10 URLs)
- 📦 Batch audits
- 📈 Historical tracking & trends (90 days)
- Email support
Pro
$39
per month
- 5,000 audits / month
- All 82 checks
- 60 requests / minute
- 🔍 SXO, AEO & AIO scores
- 5 GEO audits / month
- ♿ 100 ADA audits / month
- 📊 Score monitoring (25 URLs)
- 📦 Batch audits
- 📈 Historical tracking & trends (1 year)
- Priority support
Ultra
$99
per month
- 25,000 audits / month
- All 82 checks
- 120 requests / minute
- 🔍 SXO, AEO & AIO scores
- 10 GEO audits / month
- ♿ 500 ADA audits / month
- 📊 Score monitoring (50 URLs)
- 📦 Batch audits
- 📈 Historical tracking & trends (unlimited)
- Dedicated support
Frequently asked questions
Everything most developers and agencies ask before they sign up.
What is SEO Score API?
SEO Score API is a hosted REST API that returns a scored SEO audit for any URL in about two seconds. It runs 82 checks across on-page SEO, technical SEO, social metadata, performance, accessibility, AI readability, and SXO/AEO/AIO scoring, and returns the result as JSON your code can act on. It is built for developers and agencies who want SEO checks in code, CI/CD, or AI agents — not in a dashboard.
How is it different from PageSpeed Insights or Lighthouse?
Lighthouse and PageSpeed Insights focus on performance and Web Vitals. SEO Score API focuses on broader SEO depth: 82 checks including on-page tags, schema validation, AI readability scoring, and SXO/AEO/AIO. We are a hosted API with dedicated quotas, a GitHub Action, and SDKs — Lighthouse is a CLI/library you assemble yourself. Many teams run both. See the full SEO Score API vs Lighthouse comparison.
Can I use SEO Score API for free?
Yes. The free tier includes 2 audits per day with no credit card required. Paid plans start at $5/month for 200 audits and scale up to 25,000 audits/month. Every plan, including the free tier, includes full API access.
What does the AI readability score measure?
It measures how effectively large language models and RAG pipelines can parse and cite a page. It evaluates crawl accessibility (SSR, llms.txt, AI-bot allowlist), structural markup (semantic HTML, heading hierarchy, JSON-LD), and content extractability (answer-first sections, fact density, chunk-friendly structure). See the full methodology.
What's the difference between SEO, SXO, AEO, and AIO scores?
SEO scores how well a page ranks in traditional search results. SXO (Search Experience Optimization) scores UX signals that influence ranking. AEO (Answer Engine Optimization) scores how cleanly the page answers questions for featured snippets and AI Overviews. AIO (AI Optimization) scores ingestion by LLMs and RAG systems. All four are returned in every audit on Starter+ plans. See the launch post.
Do you have a Python or Node.js SDK?
Yes — the Python SDK is on PyPI as seoscoreapi and the Node.js SDK is on npm as seoscoreapi. We also publish an n8n community node and a GitHub Action for CI/CD pipelines. All at version 1.1.0.
Can I run SEO Score API in CI/CD?
Yes. We publish an official GitHub Action that fails the build when an SEO score drops below a threshold. It works with Vercel, Netlify, and any preview-URL setup. For GitLab, CircleCI, or other CI systems, call the API directly with curl or our SDKs.
How do I get an API key?
Enter your email below. We send a 6-digit verification code. Enter the code and you get your API key — usable immediately. No credit card required for the free tier. The whole flow takes under 30 seconds.
How does SEO Score API compare to Ahrefs, Moz, and SEMrush?
It sits alongside them, not against them. Ahrefs, Moz, and SEMrush are dashboard suites built around backlinks, keyword research, and SERP rank tracking — none of which SEO Score API does. SEO Score API is a focused REST API for automated on-page and technical SEO audits, AI readability, and CI/CD score gating. Most of our customers already use Ahrefs or Moz and add SEO Score API for the audit-in-code workflows those tools don't cover. See the full comparison.
Is this a free SEO API I can use without a credit card?
Yes. The free SEO API tier gives you 2 audits per day with no credit card. You sign up with email, verify a 6-digit code, and get a working API key in under 30 seconds. The same endpoint and SDKs work on the free tier as on paid plans — the only differences are the daily limit and which advanced scores (SXO/AEO/AIO, GEO, competitive) are bundled in.
Can I use it as an SEO checker API or SEO report API?
Yes. The same endpoint is the SEO checker API (pass/fail per check, scored 0–100, threshold against it in CI/CD), the SEO report API (full JSON breakdown plus shareable HTML reports at /report/{domain} and SVG score badges at /badge/{domain}), and the SEO audit API (82 per-URL checks). One key, one endpoint, structured JSON.
From the blog
Guides, tutorials, and worked examples — straight from the team building the API.
The SEO Report API: From One Call to a Shareable Client ReportAn SEO report API turns a single audit call into a structured report you can email to a client, embed in a dashboard, or attach to a Slack a
The SEO Checker API: Pass/Fail SEO Checks for Code, Not DashboardsAn SEO checker API returns structured pass/fail results for every check so your code can threshold, diff, and gate on them. The difference b
Continuous SEO Monitoring for SaaS Marketing SitesSaaS marketing sites get touched constantly — new landing pages, new pricing, new docs. Continuous monitoring catches the regressions PMs an
Headless CMS SEO Audits: Contentful, Sanity, and StrapiHeadless CMS sites have a structural SEO problem — content lives in one system, rendering lives in another, and the gap is where things brea
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