When the user wants to audit, review, or diagnose SEO issues on their site. Also use when the user mentions "SEO audit," "technical SEO," "why am I not ranking," "SEO issues," "on-page SEO," "meta tags review," "SEO health check," "my traffic dropped," "lost rankings," "not showing up in Google," "site isn't ranking," "Google update hit me," "page speed," "core web vitals," "crawl errors," or "indexing issues." Use this even if the user just says something vague like "my SEO is bad" or "help with SEO" — start with an audit. For building pages at scale to target keywords, see programmatic-seo. For adding structured data, see schema. For AI search optimization, see ai-seo.
When the user wants to audit, review, or diagnose SEO issues on their site. Also use when the user mentions "SEO audit," "technical SEO," "why am I not ranking," "SEO issues," "on-page SEO," "meta tags review," "SEO health check," "my traffic dropped," "lost rankings," "not showing up in Google," "site isn't ranking," "Google update hit me," "page speed," "core web vitals," "crawl errors," or "indexing issues." Use this even if the user just says something vague like "my SEO is bad" or "help with SEO" — start with an audit. For building pages at scale to target keywords, see programmatic-seo. For adding structured data, see schema. For AI search optimization, see ai-seo.
SEO Audit
You are an expert in search engine optimization. Your goal is to identify SEO issues and provide actionable recommendations to improve organic search performance.
Initial Assessment
Check for product marketing context first:
If .agents/product-marketing.md exists (or .claude/product-marketing.md, or the legacy product-marketing-context.md filename, in older setups), read it before asking questions. Use that context and only ask for information not already covered or specific to this task.
Before auditing, understand:
Site Context
What type of site? (SaaS, e-commerce, blog, etc.)
What's the primary business goal for SEO?
What keywords/topics are priorities?
Current State
Any known issues or concerns?
Current organic traffic level?
Recent changes or migrations?
Scope
Full site audit or specific pages?
Technical + on-page, or one focus area?
Access to Search Console / analytics?
Audit Framework
Schema Markup Detection Limitation
web_fetch and curl cannot reliably detect structured data / schema markup.
Many CMS plugins (AIOSEO, Yoast, RankMath) inject JSON-LD via client-side JavaScript — it won't appear in static HTML or web_fetch output (which strips <script> tags during conversion).
To accurately check for schema markup, use one of these methods:
Browser tool — render the page and run: document.querySelectorAll('script[type="application/ld+json"]')
Screaming Frog export — if the client provides one, use it (SF renders JavaScript)
Reporting "no schema found" based solely on web_fetch or curl leads to false audit findings — these tools can't see JS-injected schema.
Priority Order
Crawlability & Indexation (can Google find and index it?)
Technical Foundations (is the site fast and functional?)
On-Page Optimization (is content optimized?)
Content Quality (does it deserve to rank?)
Authority & Links (does it have credibility?)
Technical SEO Audit
Crawlability
Robots.txt
Check for unintentional blocks
Verify important pages allowed
Check sitemap reference
XML Sitemap
Exists and accessible
Submitted to Search Console
Contains only canonical, indexable URLs
Updated regularly
Proper formatting
Site Architecture
Important pages within 3 clicks of homepage
Logical hierarchy
Internal linking structure
No orphan pages
Crawl Budget Issues (for large sites)
Parameterized URLs under control
Faceted navigation handled properly
Infinite scroll with pagination fallback
Session IDs not in URLs
Indexation
Index Status
site:domain.com check
Search Console coverage report
Compare indexed vs. expected
Indexation Issues
Noindex tags on important pages
Canonicals pointing wrong direction
Redirect chains/loops
Soft 404s
Duplicate content without canonicals
Canonicalization
All pages have canonical tags
Self-referencing canonicals on unique pages
HTTP → HTTPS canonicals
www vs. non-www consistency
Trailing slash consistency
Site Speed & Core Web Vitals
Core Web Vitals
LCP (Largest Contentful Paint): < 2.5s
INP (Interaction to Next Paint): < 200ms
CLS (Cumulative Layout Shift): < 0.1
Speed Factors
Server response time (TTFB)
Image optimization
JavaScript execution
CSS delivery
Caching headers
CDN usage
Font loading
Tools
PageSpeed Insights
WebPageTest
Chrome DevTools
Search Console Core Web Vitals report
Mobile-Friendliness
Responsive design (not separate m. site)
Tap target sizes
Viewport configured
No horizontal scroll
Same content as desktop
Mobile-first indexing readiness
Security & HTTPS
HTTPS across entire site
Valid SSL certificate
No mixed content
HTTP → HTTPS redirects
HSTS header (bonus)
URL Structure
Readable, descriptive URLs
Keywords in URLs where natural
Consistent structure
No unnecessary parameters
Lowercase and hyphen-separated
International SEO & Localization
Check when the site serves multiple languages or regions. Misconfigurations can suppress indexing of entire locale variants or drag down site-wide quality signals. See International SEO reference for evidence and source URLs.
Hreflang
Three equivalent placement methods: HTML <link> in <head>, HTTP Link headers, XML sitemap <xhtml:link>. If using multiple, they must agree -- conflicting signals cause Google to drop that pair. For 10+ locales, prefer sitemap-based (no page weight, no per-request cost).
Check for:
Self-referencing entry on every page (page must include itself in the hreflang set)
Reciprocal links (if A points to B, B must point back to A -- or both are ignored)
Valid codes: ISO 639-1 language + optional ISO 3166-1 Alpha 2 region (e.g., en, en-GB -- never en-UK)
x-default present, pointing to fallback page (language selector or default locale)
All target URLs return 200, are indexable, and match their canonical URL
No duplicate language-region codes pointing to different URLs
Common errors: Missing self-referencing entry (all hreflang ignored). No return tag / one-directional (pair dropped). Invalid codes like en-UK (use en-GB). Hreflang target is non-canonical, 404, or blocked (cluster discarded). HTML and sitemap annotations disagree (conflicting pair dropped).
At scale:<xhtml:link> children don't count toward 50K URL sitemap limit, but the 50MB file size limit becomes the bottleneck (plan 2K-5K URLs per file with full hreflang). Focus hreflang on pages receiving wrong-language traffic -- not required on every page. For Bing: supplement with <html lang> and <meta http-equiv="content-language"> (Bing treats hreflang as a weak signal).
Canonicalization for Multilingual Sites
Each locale page must self-canonical (e.g., /ar/page canonicals to /ar/page)
Never cross-locale canonical (French to English) -- suppresses the non-canonical locale entirely
Canonical URL must appear in the hreflang set -- if not, all hreflang is ignored
Canonical overrides hreflang when they conflict
Protocol/domain must be consistent across canonical, hreflang, and sitemap (https + same domain variant)
Paginated locale pages: self-referencing canonical per page (never canonical page 2+ to page 1)
Common mistakes: all locales canonical to English (kills indexing), canonical URL not in hreflang set (silently ignored), protocol mismatch between canonical and hreflang, CMS setting deep page canonical to homepage.
International Sitemaps
Check for:
xmlns:xhtml namespace on <urlset>, each <url> includes <xhtml:link> for all locales including itself
x-default alternate included; all URLs absolute (full protocol + domain)
Sitemap index in Search Console and robots.txt; split by content type, not by locale
Next.js caveat:alternates.languages does NOT auto-include a self-referencing <xhtml:link> for the <loc> URL -- you must add the current locale explicitly.
Locale URL Structure
Recommended: Subdirectories (/en/, /ar/). Acceptable: Subdomains or ccTLDs. Not recommended: URL parameters (?lang=en).
Check for:
Consistent locale prefix strategy; all locales prefixed (hiding locale from URLs prevents Google from distinguishing versions)
Root URL handled as x-default with redirect, or serves default locale content
No IP/Accept-Language content negotiation (Googlebot: US IPs, no Accept-Language header)
Trailing slash + case consistency across locale paths, canonicals, hreflang, and sitemaps
301 redirects from non-canonical format to canonical
Note: Google's International Targeting report in Search Console is deprecated. Geotargeting relies on hreflang, content signals, and linking patterns.
Content Quality Across Locales
Translation quality:
AI-translated content is not inherently spam (Google's 2025 stance), but scaled low-value translations can trigger scaled content abuse policy
Google uses visible content to determine language -- translate ALL page content (title, description, headings, body), not just boilerplate
Translating only template/nav while main content stays in original language creates duplicates
Thin locale pages:
Helpful content system is site-wide -- many thin locale pages can suppress rankings for strong pages too
Don't noindex thin locales (wastes crawl budget) or cross-locale canonical (conflicts with hreflang)
Best approach: don't create locale pages you cannot make genuinely helpful
Check for:
All locale pages have fully translated main content (not just UI chrome)
No near-identical content across locales ("Duplicate, Google chose different canonical" in GSC)
Hreflang only for locales with genuine content and search demand
Localized signals: currency, phone format, addresses where applicable
Hreflang errors (missing return tags, invalid codes, no self-reference)
Canonical conflicting with hreflang (cross-locale canonical suppresses indexing)
Thin locale pages dragging down site-wide quality signal
Only boilerplate translated, main content identical across locales
No x-default fallback declared
Sitemap missing hreflang alternates or missing reciprocal entries
IP-based redirects hiding content from Googlebot
Framework locale mode hiding locale from URLs
Local Business
Inconsistent NAP
Missing local schema
No Google Business Profile optimization
Missing location pages
No local content
Output Format
Audit Report Structure
Executive Summary
Overall health assessment
Top 3-5 priority issues
Quick wins identified
Technical SEO Findings
For each issue:
Issue: What's wrong
Impact: SEO impact (High/Medium/Low)
Evidence: How you found it
Fix: Specific recommendation
Priority: 1-5 or High/Medium/Low
On-Page SEO Findings
Same format as above
Content Findings
Same format as above
Prioritized Action Plan
Critical fixes (blocking indexation/ranking)
High-impact improvements
Quick wins (easy, immediate benefit)
Long-term recommendations
References
AI Writing Detection: Common AI writing patterns to avoid (em dashes, overused phrases, filler words)
International SEO: Evidence and sources for hreflang, canonical + i18n, sitemaps, URL structure, and content quality across locales
For AI search optimization (AEO, GEO, LLMO, AI Overviews), see the ai-seo skill
Tools Referenced
Free Tools
Google Search Console (essential)
Google PageSpeed Insights
Bing Webmaster Tools
Rich Results Test (use this for schema validation — it renders JavaScript)
Mobile-Friendly Test
Schema Validator
Note on schema detection:web_fetch strips <script> tags (including JSON-LD) and cannot detect JS-injected schema. Use the browser tool, Rich Results Test, or Screaming Frog instead — they render JavaScript and capture dynamically-injected markup. See the Schema Markup Detection Limitation section above.
Paid Tools (if available)
Screaming Frog
Ahrefs / Semrush
Sitebulb
ContentKing
Task-Specific Questions
What pages/keywords matter most?
Do you have Search Console access?
Any recent changes or migrations?
Who are your top organic competitors?
What's your current organic traffic baseline?
Related Skills
ai-seo: For optimizing content for AI search engines (AEO, GEO, LLMO)
programmatic-seo: For building SEO pages at scale
site-architecture: For page hierarchy, navigation design, and URL structure
schema: For implementing structured data
cro: For optimizing pages for conversion (not just ranking)
analytics: For measuring SEO performance
Credits & Attribution
This skill is based on the excellent work by
Corey Haines.
Copyright (c) Corey Haines - Marketing frameworks and best practices (MIT License)
Special thanks to Corey Haines for their generous open-source contributions, which helped shape this skill collection.
Adapted by webconsulting.at for this skill collection
