# seo-audit-skill
**English** · [中文](README.zh.md) · [SEO Audit Agent Skill](https://nanoskill.ai/skills/seo-audit)
Reusable Agent Skills for single-page SEO auditing. Give it a URL — get a structured HTML report with actionable findings.
Built on a **Script + LLM two-layer architecture**: Python scripts handle deterministic checks (HTTP status, XML parsing, string matching), while the LLM handles semantic judgment (keyword intent, content quality, page type inference). Works with Claude Code, Cursor, and any agent runtime that supports SKILL.md.
## Best practices
1. Run `npx skills add JeffLi1993/seo-audit-skill`, then audit your page (for example: `audit this page: https://example.com`). Open the report at `reports/<hostname>-audit.html` and review it yourself: keep what matters for your goals, skip what does not.
2. Share the report (or the key sections) with Cursor or Claude Code and have the assistant work through the findings and fixes item by item.
---
## Report Output
Each basic audit produces a standalone HTML report saved to `reports/<hostname>-audit.html`.
Full audits save to `reports/<hostname>-full-audit.html`.
| Section | What you get |
|---|---|
| **Audit Summary** | One-line verdict + critical / warnings / passing at a glance |
| **Site Checks** | Sitemap URL Inventory · Crawlability · URL Canonicalization · i18n · Schema · E-E-A-T |
| **Page Speed** | Full only — Lighthouse scores, lab metrics, final URL, screenshot availability |
| **Page Checks** | TDK · H1 · Headings · Word Count · Internal Links · Social Tags |
| **Priority Actions** | Top 3 highest-impact fixes, ranked |
| **Insight Walkthrough** | Evidence → Impact → Fix for each major finding |
```
audit this page: https://openclaw.ai
→ ✅ Report saved → reports/openclaw-ai-audit.html
```
| Website | Audit Summary | Site Checks | Page Checks & insights |
|---|---|---|---|
| colaos.ai | <img src="assets/0-0.png" alt="Audit Summary" width="240" /> | <img src="assets/0-1.png" alt="Site Checks" width="240" /> | <img src="assets/0-2.png" alt="Page Checks and insights" width="240" /> |
---
## Skills
| Skill | Tier | When to use |
|---|---|---|
| `seo-audit` | Basic | Default — give it a URL, get a 20+ check structured report |
| `seo-audit-full` | Full | Deep audit with PageSpeed, sitemap inventory, social tags, content quality, GSC data, competitor gap |
> `seo-audit-full` requires a Google PageSpeed Insights API key for PageSpeed checks. Set `PAGESPEED_API_KEY` / `GOOGLE_PAGESPEED_API_KEY`, or pass `--api-key`; without a key, the full audit stops and asks you to configure one.
---
## Audit Coverage
### Site-level
| Check | What it verifies | Basic | Full |
|---|---|:---:|:---:|
| Sitemap URL Inventory | Standalone table of top sitemap directories: URL count, page type, representative example URL | — | ✅ |
| Staging Subdomain Indexation | Detects public `test.`, `staging.`, `dev.`, `preview.`, `beta.`, `uat.` hosts that mirror production and may be indexable | — | ✅ |
| robots.txt | RFC 9309 group parsing, Allow/Disallow logic, Googlebot status, Sitemap directives | ✅ | ✅ |
| sitemap.xml | Valid XML, URL count, follows Sitemap directive path from robots.txt, samples child sitemap URLs when needed | ✅ | ✅ |
| 404 Handling | True 404 vs soft 404 (200) vs redirect-to-homepage (301) | ✅ | ✅ |
| URL Canonicalization | HTTP→HTTPS redirect, www consistency, trailing slash, canonical tag match | ✅ | ✅ |
| i18n / hreflang | Reciprocal symmetry, BCP 47 codes, x-default, default-language URL duplication, canonical/hreflang alignment | ✅ | ✅ |
| Schema (JSON-LD) | Parseability, @type detection, required/recommended fields, nested fields, type conflicts, localized schema language/URL alignment | ✅ | ✅ |
| E-E-A-T Trust Pages | About / Contact / Privacy / Terms — exists (HTTP 200) + reachable from footer/nav | ✅ | ✅ |
| GSC Crawl Status | Index coverage, crawl errors, blocked resources | — | ✅ |
| PageSpeed / Lighthouse | Performance · Accessibility · Best Practices · SEO scores, lab metrics, final URL, screenshot availability | — | ✅ |
`Sitemap URL Inventory` is intentionally rendered as its own table before Crawlability:
| Directory | URL Count | Page Type | Example Page |
|---|---:|---|---|
| `/blog/` | 300 | Blog / Content Pages | `https://xx.ai/blog/best-ai-video-tools` |
| `/tools/` | 80 | Tool Pages | `https://xx.ai/tools/image-generator` |
| `/alternatives/` | 40 | Alternative / Competitor Pages | `https://xx.ai/alternatives/synthesia` |
Use it as a site-level map, then choose representative URLs from important directories for deeper full audits.
### Page-level
| Check | What it verifies | Basic | Full |
|---|---|:---:|:---:|
| URL Slug | Lowercase, hyphenated, keyword present, stop word & stuffing detection | ✅ | ✅ |
| Title Tag | 50–60 chars, keyword position, homepage vs inner page rules | ✅ | ✅ |
| Meta Description | 120–160 chars, keyword match, concrete value prop (not generic fluff) | ✅ | ✅ |
| H1 Tag | Single H1, keyword match (full / partial / none), semantic intent review | ✅ | ✅ |
| Canonical Tag | Self-referencing, matches final URL after redirects | ✅ | ✅ |
| Image Alt Text | Alt attribute check on all `<img>`, JS-render detection | ✅ | ✅ |
| Word Count | Body text ≥ 500 words, thin content flag | ✅ | ✅ |
| Keyword Placement | Primary keyword within first 100 body words | ✅ | ✅ |
| Heading Structure | H2 count (target 5–7), H3/H2 ratio, keyword distribution in H2s | ✅ | ✅ |
| Internal Links | Same-origin links (excl. nav/footer), equity distribution | ✅ | ✅ |
| OG / Social Tags | og:image, twitter:card, social preview completeness | — | ✅ |
| Content Quality | E-E-A-T depth, readability, specificity vs competitors | — | ✅ |
| Robots Meta | noindex, nofollow, max-snippet directives | — | ✅ |
---
## Structure
```
seo-audit-skill/
├── seo-audit/
│ ├── SKILL.md # Skill definition + agent workflow
│ ├── references/REFERENCE.md # Field definitions, edge cases
│ ├── assets/report-template.html # HTML output template
│ └── scripts/
│ ├── check-site.py # robots.txt + sitemap → JSON
│ ├── check-page.py # TDK + H1 + canonical + slug → JSON
│ ├── check-schema.py # JSON-LD extraction + validation → JSON
│ └── fetch-page.py # Raw HTML fetcher, SSRF protection
└── seo-audit-full/
├── SKILL.md
├── references/REFERENCE.md
├── assets/report-template.html
└── scripts/
├── check-site.py # staging + sitemap inventory + robots/sitemap → JSON
├── check-pagespeed.py # PageSpeed Insights / Lighthouse → JSON
├── check-social.py # OG + Twitter Card validation → JSON
└── check-schema.py # JSON-LD quality + localized schema validation → JSON
```
---
## Architecture: Script + LLM
```
URL
│
▼
┌──────────────────────────────────────────────────┐
│ Layer 1 · Python Scripts │
│ Deterministic checks → structured JSON │
│ │
│ check-site.py sitemap inventory, staging │
│ check-page.py H1 / title / meta / canonical│
│ check-schema.py JSON-LD fields + localization│
│ fetch-page.py raw HTML + SSRF protection │
└───────────────────────┬──────────────────────────┘
│ JSON + llm_review_required flag
▼
┌──────────────────────────────────────────────────┐
│ Layer 2 · LLM Agent │
│ Semantic judgment on flagged fields only │
│ │
│ · Keyword intent alignment (H1 / title) │
│ · Meta description quality & specificity │
│ · Page type → expected Schema @type mapping │
│ · E-E-A-T trust page reachability (footer/nav) │
│ · Content analysis (word count, heading, links) │
└───────────────────────┬──────────────────────────┘
│
▼
report-template.html
→ reports/<hostname>-audit.html
```
**Why two layers?** Scripts handle the 80% of checks that are deterministic — does `robots.txt` exist? Is the title 55 characters? The LLM handles the 20% that require understanding — does this H1 semantically cover the intent of "AI workflow automation"? The `llm_review_required` flag ensures the LLM only intervenes when the script explicitly cannot make the call. No hallucination on factual checks, no blind spots on semantic ones.
---
## Installation
**Option 1: CLI (Recommended)**
```bash
npx skills add JeffLi1993/seo-audit-skill
# Or install a specific tier
npx skills add JeffLi1993/seo-audit-skill --skill seo-audit
npx skills add JeffLi1993/seo-audit-skill --skill seo-audit-full
```
**Option 2: Claude Code Plugin**
```bash
/plugin marketplace add JeffLi1993/seo-audit-skill
/plugin install seo-audit-skill
```
## Usage
```
audit this page: https://example.com
```
---
## Scripts
All scripts output structured JSON to stdout. Exit code `0` = pass/warn, `1` = any fail.
| Script | What it does |
|---|---|
| `check-site.py` | robots.txt + sitemap + sitemap inventory — RFC 9309 parsing, staging subdomain checks, top directory grouping |
| `check-page.py` | H1 / title / meta / canonical / URL slug — keyword match with stop-word-aware filter |
| `check-schema.py` | JSON-LD extraction, @graph flattening, @type + required field validation, localized schema alignment |
| `fetch-page.py` | Raw HTML fetch — SSRF protection, redirect chain tracking, Googlebot UA option |
| `check-pagespeed.py` | Full only — PageSpeed Insights / Lighthouse scores and lab metrics; requires API key |
| `check-social.py` | Full only — OG tags + Twitter Card validation |
**Dependency:** `pip install requests`
---
## License
MIT