Technical SEO Implementation
This skill is the implementation reference for technical SEO. Use it when you need to add, fix, or optimize SEO elements in code — meta tags, schema markup, Core Web Vitals, crawlability, and GEO.
This skill covers how to implement in code. For the other SEO concerns:
- seo — Strategy and planning (keyword research, content architecture, what to build)
- seo-content — Writing content (briefs, humanized prose, SERP feature targeting)
- seo-audit — Auditing an existing codebase (scan, diagnose, produce action plan)
Metadata
Every indexable page needs these elements correct:
- Title tag: 50-60 chars, primary keyword front-loaded
- Meta description: 120-155 chars, includes CTA
- Canonical: self-referencing or correct target
- Robots: no accidental noindex
- Open Graph: og:title, og:description, og:image for social sharing
For detailed specs and code examples, see ON-PAGE-SEO.md.
HTML Structure
- Exactly one H1 per page, contains primary keyword
- No skipped header levels (H1 → H2 → H3)
- Semantic HTML:
<header>,<nav>,<main>,<article>,<section>
Crawlability
- robots.txt exists, not blocking important paths
- XML sitemap exists, all important URLs included
- Canonical tags on every page
- No orphan pages, proper internal linking
For detailed crawlability checklist, see TECHNICAL-AUDIT.md.
Core Web Vitals
Target metrics (2026 thresholds):
| Metric | Good | Needs Improvement | Poor |
|---|---|---|---|
| LCP (Largest Contentful Paint) | ≤ 2.5s | 2.5s - 4s | > 4s |
| INP (Interaction to Next Paint) | ≤ 200ms | 200ms - 500ms | > 500ms |
| CLS (Cumulative Layout Shift) | ≤ 0.1 | 0.1 - 0.25 | > 0.25 |
Note: INP replaced FID as a Core Web Vital in March 2024.
For optimization techniques (LCP, INP, CLS), see TECHNICAL-AUDIT.md.
E-E-A-T & Schema
| Signal | Implementation |
|---|---|
| Experience | First-hand testing, case studies, original photos |
| Expertise | Author credentials, certifications |
| Authoritativeness | Quality backlinks, industry mentions |
| Trustworthiness | HTTPS, contact info, privacy policy, citations |
Required JSON-LD schema: Organization, WebSite, Article/BlogPosting, FAQPage, BreadcrumbList, Person (author).
For schema code examples and author bio templates, see EEAT-AND-SCHEMA.md.
GEO (Generative Engine Optimization)
Optimize for AI-powered search engines:
| Aspect | Traditional SEO | GEO |
|---|---|---|
| Goal | Rank in search results | Be cited in AI answers |
| Success Metric | Click-through rate | Citation frequency |
| Approach | Keywords, backlinks | Entity clarity, authority signals |
| Optimization | Pages and snippets | Citable facts and answers |
For GEO techniques, llms.txt implementation, and AI crawler management, see GEO.md.
Fix Priorities
When issues are identified, fix in this order:
Priority 1: Critical (Fix Immediately)
- 404 errors and broken links
- Missing or duplicate title tags
- Broken canonical tags
- noindex on important pages
- HTTPS/security issues
- Blocked by robots.txt
Priority 2: High (Fix Within 1 Week)
- Core Web Vitals failures
- Missing meta descriptions
- Multiple H1 tags
- Missing alt text on key images
- Orphan pages (no internal links)
- Missing schema markup
Priority 3: Medium (Fix Within 1 Month)
- Thin content pages
- Header hierarchy issues
- Internal link optimization
- Image optimization (format, compression)
- Anchor text improvements
- Content freshness updates
Priority 4: Low (Ongoing Optimization)
- A/B testing improvements
- Advanced schema types
- International SEO expansion
- New content for topic clusters
- Competitive gap analysis
Post-Fix Validation
After applying fixes:
- Re-crawl the affected pages
- Verify DOM changes are live
- Check robots.txt isn't blocking new paths
- Validate schema with Google's Rich Results Test
- Test Core Web Vitals with Lighthouse
- Monitor Search Console for indexing issues
Monitoring Cadence
Daily: Check Search Console for crawl errors. Monitor site uptime. Review security alerts.
Weekly: Review Core Web Vitals trends. Check for new 404s. Monitor AI referral traffic. Review ranking changes.
Monthly: Full technical audit. Content freshness review. Backlink profile analysis. Schema validation.
Quarterly: Full SEO strategy review. GEO performance analysis. Content gap analysis.
Quick Reference
SEO Specifications
| Element | Specification |
|---|---|
| Title Tag | 50-60 chars, keyword front-loaded |
| Meta Description | 120-155 chars, includes CTA |
| H1 | Exactly 1 per page, contains keyword |
| URL | Lowercase, hyphens, descriptive |
| Images | WebP/AVIF, <200KB, alt text, dimensions |
| Canonical | Self-referencing on every page |
| robots.txt | Allow important paths, block admin |
| Sitemap | All indexable URLs, lastmod dates |
GEO Checklist
| Element | Required |
|---|---|
| FAQPage Schema | Yes |
| Answer-first content | Yes |
| Statistics with sources | Yes |
| Expert quotes | Recommended |
| TL;DR blocks | Recommended |
| llms.txt | Recommended |
| Fresh content (<90 days) | Yes |
Supporting Files
- TECHNICAL-AUDIT.md — Core Web Vitals optimization, crawlability, mobile-first, HTTPS
- ON-PAGE-SEO.md — Title tags, meta descriptions, headers, images, internal linking
- EEAT-AND-SCHEMA.md — E-E-A-T implementation, schema markup library (JSON-LD)
- GEO.md — Generative Engine Optimization, llms.txt, AI crawlers, framework-specific SEO
Version History
- v3.0 (March 2026): Reframed as implementation reference (auditing moved to seo-audit skill), added cross-references to seo-content and seo skills, standardized meta description spec to 120-155 chars
- v2.0 (December 2025): Added GEO section, AI crawler management, llms.txt, GA4 AI tracking, updated Core Web Vitals (INP), expanded schema library, framework-specific guides
- v1.0 (December 2024): Initial version with technical audit, on-page SEO, basic schema