The free SEO audit API.
One call. 80+ checks per URL.

SEO Score API is a hosted REST API that returns a scored SEO audit for any URL in seconds. It runs 80+ 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.

The standard /audit endpoint runs 80+ checks on a single URL and returns scored JSON in seconds — ideal for CI/CD, monitoring, and per-page grading. Deep Site Audit is a separate, asynchronous audit (about 90 seconds) built on a catalog of 14,000+ checks across nine dimensions: it scores the thousands of checks that apply to the page, adds an AI analysis pass of up to 150 checks, and scans the served source for exposed secrets. It's designed for agencies and teams that need the full picture rather than a fast per-URL score. Pro includes 20 Deep Site Audits a month and Ultra 100; any plan can buy credit packs. See the API docs.

Lighthouse and PageSpeed Insights focus on performance and Web Vitals. SEO Score API focuses on broader SEO depth: 80+ 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.

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.

Yes. Every paid plan can be billed yearly for the price of 10 months, so two months are free: Starter $50/year, Basic $150/year, Pro $390/year and Ultra $990/year. The allowances stay monthly, so an annual Pro plan still gets 5,000 audits every month. Need more volume, custom limits or an invoice? See Enterprise.

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.

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.

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.

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.

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.

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.

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.

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 (80+ per-URL checks). One key, one endpoint, structured JSON.