SEO Assets — Schema, Sitemaps & Images
Part 1: Schema Markup
Detection
- JSON-LD:
<script type="application/ld+json">
- Microdata:
itemscope, itemtype, itemprop
- RDFa:
typeof, property, vocab
- Note delivery method (server-rendered vs JS-injected — JS faces delayed processing)
Validation
| Error |
Severity |
Fix |
Missing @context |
Critical |
Add "@context": "https://schema.org" |
Missing/invalid @type |
Critical |
Use exact Schema.org type name |
| Relative URLs |
High |
Use absolute HTTPS URLs |
| Invalid ISO 8601 date |
High |
Use YYYY-MM-DD |
| Deprecated type |
Critical |
Replace with active alternative |
aggregateRating zero reviews |
High |
Minimum 1 review required |
Schema Type Status (March 2026)
ACTIVE: Organization, LocalBusiness, Person, ProfilePage, Article, BlogPosting, NewsArticle, WebPage, WebSite, Product, ProductGroup, Offer, Service, VideoObject, ImageObject, Review, AggregateRating, BreadcrumbList, Event, JobPosting, Course, SoftwareApplication, DiscussionForumPosting
RESTRICTED: FAQ — ONLY government/healthcare (Aug 2023)
DEPRECATED — Never recommend: HowTo (Sept 2023), SpecialAnnouncement (July 2025), CourseInfo/EstimatedSalary/LearningVideo/ClaimReview/VehicleListing (June 2025), Practice Problem/Dataset (late 2025)
See ../seo-core/references/schema-types.md for full details.
JSON-LD Templates
See references/schema-templates.md for ready-to-use templates: Product, Article/BlogPosting, LocalBusiness, Organization, BreadcrumbList, WebSite, SoftwareApplication.
Schema and AI Overviews
- Organization + sameAs: AI brand entity identification
- Article + dateModified: increases citation likelihood
- Product + complete Offer: enables product cards in AI responses
- Person schema on author pages: builds E-E-A-T signals
Output: SCHEMA-RECOMMENDATIONS.md
Detection results, validation results, missing opportunities with CTR impact, GSC fix priority, generated-schema.json with placement instructions.
Part 2: Sitemaps
<priority> and <changefreq> ignored by Google — omit them.
Analyze Existing Sitemap
Locate: /sitemap.xml > /sitemap_index.xml > robots.txt Sitemap: directive
Validate: Valid XML, correct namespace, <50,000 URLs/file, <50MB uncompressed. All URLs return 200, no redirects, no noindex, only canonical URLs.
Coverage: Compare sitemap vs crawled vs indexed pages.
Exclude: Noindex, non-canonical, paginated (2+), filtered/faceted, login, thin (<300 words), parameter URLs, session IDs, admin/staging.
Generate New Sitemap
| Scale |
Approach |
| <1,000 URLs |
Single sitemap.xml |
| 1k-50k |
Single or split by type |
| 50k-500k |
Sitemap index, multiple files |
| >500k |
Sitemap index, split by section + date |
CMS: WordPress (Yoast/Rank Math), Webflow (built-in), Next.js (/app/sitemap.js), Shopify (built-in), static sites (Hugo/Jekyll/Eleventy plugins).
lastmod: Must reflect actual modification date. Never set today's date on all pages.
Sitemap Formats
- Standard:
<urlset> with <url><loc> and <lastmod> only
- Index:
<sitemapindex> referencing multiple files
- Image:
xmlns:image namespace, up to 1,000 images per URL
- Video:
xmlns:video namespace, thumbnail/title/description required
Always declare in robots.txt: Sitemap: https://example.com/sitemap.xml
Output: SITEMAP-VALIDATION-REPORT.md
Summary, issues table with severity, coverage gap analysis, prioritized recommendations.
Part 3: Image Optimization
See references/image-optimization.md for file size thresholds, format selection, LCP image rules, responsive images, lazy loading, CLS prevention, and AI citability.
Analysis Checklist
- Alt text: Present on all non-decorative images; descriptive, contextual; 10-125 chars; decorative =
alt=""
- File size: Check against thresholds in reference file
- Format: AVIF > WebP > JPEG; SVG for icons; video for large GIFs
- Responsive: srcset with 2+ widths; sizes matching breakpoints
- LCP image:
fetchpriority="high", no lazy-load, no decoding="async", in initial HTML
- Lazy loading:
loading="lazy" only on below-fold images
- CLS: width/height on all
<img> or CSS aspect-ratio
- File names: Descriptive, hyphenated, lowercase, <60 chars
- CDN: Recommend for >50 images or global audience
- ImageObject schema: For editorial/product/author photos
Output: IMAGE-OPTIMIZATION.md
Audit summary table, prioritized optimization list, recommendations by severity, corrected HTML snippets.
1---2name: seo-assets3description: Schema.org (JSON-LD), sitemaps XML e imágenes SEO. Rich results, rich snippets, knowledge panels, WebP/AVIF, alt text, LCP de imagen, CLS, srcset. Usar cuando: "schema", "datos estructurados", "JSON-LD", "rich results", "sitemap XML", "optimizar imágenes", "alt text", "WebP", "AVIF", "LCP imagen", "image SEO", "srcset", "lazy loading", "errores schema GSC". "Google Images", "image compression", "fetchpriority", "CLS images", "Product schema", "Article schema", "LocalBusiness schema", "BreadcrumbList", "sitemap not found", "pages not indexed", "crawl coverage", or asks about rich result appearance, schema errors, sitemap generation, or image performance.4---56# SEO Assets — Schema, Sitemaps & Images78---910## Part 1: Schema Markup1112### Detection131. JSON-LD: `<script type="application/ld+json">`142. Microdata: `itemscope`, `itemtype`, `itemprop`153. RDFa: `typeof`, `property`, `vocab`164. Note delivery method (server-rendered vs JS-injected — JS faces delayed processing)1718### Validation1920| Error | Severity | Fix |21|-------|----------|-----|22| Missing `@context` | Critical | Add `"@context": "https://schema.org"` |23| Missing/invalid `@type` | Critical | Use exact Schema.org type name |24| Relative URLs | High | Use absolute HTTPS URLs |25| Invalid ISO 8601 date | High | Use `YYYY-MM-DD` |26| Deprecated type | Critical | Replace with active alternative |27| `aggregateRating` zero reviews | High | Minimum 1 review required |2829### Schema Type Status (March 2026)3031**ACTIVE:** Organization, LocalBusiness, Person, ProfilePage, Article, BlogPosting, NewsArticle, WebPage, WebSite, Product, ProductGroup, Offer, Service, VideoObject, ImageObject, Review, AggregateRating, BreadcrumbList, Event, JobPosting, Course, SoftwareApplication, DiscussionForumPosting3233**RESTRICTED:** FAQ — ONLY government/healthcare (Aug 2023)3435**DEPRECATED — Never recommend:** HowTo (Sept 2023), SpecialAnnouncement (July 2025), CourseInfo/EstimatedSalary/LearningVideo/ClaimReview/VehicleListing (June 2025), Practice Problem/Dataset (late 2025)3637See `../seo-core/references/schema-types.md` for full details.3839### JSON-LD Templates40See `references/schema-templates.md` for ready-to-use templates: Product, Article/BlogPosting, LocalBusiness, Organization, BreadcrumbList, WebSite, SoftwareApplication.4142### Schema and AI Overviews43- Organization + sameAs: AI brand entity identification44- Article + dateModified: increases citation likelihood45- Product + complete Offer: enables product cards in AI responses46- Person schema on author pages: builds E-E-A-T signals4748### Output: SCHEMA-RECOMMENDATIONS.md49Detection results, validation results, missing opportunities with CTR impact, GSC fix priority, generated-schema.json with placement instructions.5051---5253## Part 2: Sitemaps5455`<priority>` and `<changefreq>` ignored by Google — omit them.5657### Analyze Existing Sitemap58**Locate:** `/sitemap.xml` > `/sitemap_index.xml` > robots.txt `Sitemap:` directive5960**Validate:** Valid XML, correct namespace, <50,000 URLs/file, <50MB uncompressed. All URLs return 200, no redirects, no noindex, only canonical URLs.6162**Coverage:** Compare sitemap vs crawled vs indexed pages.6364**Exclude:** Noindex, non-canonical, paginated (2+), filtered/faceted, login, thin (<300 words), parameter URLs, session IDs, admin/staging.6566### Generate New Sitemap6768| Scale | Approach |69|-------|----------|70| <1,000 URLs | Single sitemap.xml |71| 1k-50k | Single or split by type |72| 50k-500k | Sitemap index, multiple files |73| >500k | Sitemap index, split by section + date |7475**CMS:** WordPress (Yoast/Rank Math), Webflow (built-in), Next.js (`/app/sitemap.js`), Shopify (built-in), static sites (Hugo/Jekyll/Eleventy plugins).7677**lastmod:** Must reflect actual modification date. Never set today's date on all pages.7879### Sitemap Formats80- **Standard:** `<urlset>` with `<url><loc>` and `<lastmod>` only81- **Index:** `<sitemapindex>` referencing multiple files82- **Image:** `xmlns:image` namespace, up to 1,000 images per URL83- **Video:** `xmlns:video` namespace, thumbnail/title/description required8485Always declare in robots.txt: `Sitemap: https://example.com/sitemap.xml`8687### Output: SITEMAP-VALIDATION-REPORT.md88Summary, issues table with severity, coverage gap analysis, prioritized recommendations.8990---9192## Part 3: Image Optimization9394See `references/image-optimization.md` for file size thresholds, format selection, LCP image rules, responsive images, lazy loading, CLS prevention, and AI citability.9596### Analysis Checklist971. **Alt text:** Present on all non-decorative images; descriptive, contextual; 10-125 chars; decorative = `alt=""`982. **File size:** Check against thresholds in reference file993. **Format:** AVIF > WebP > JPEG; SVG for icons; video for large GIFs1004. **Responsive:** srcset with 2+ widths; sizes matching breakpoints1015. **LCP image:** `fetchpriority="high"`, no lazy-load, no decoding="async", in initial HTML1026. **Lazy loading:** `loading="lazy"` only on below-fold images1037. **CLS:** width/height on all `<img>` or CSS `aspect-ratio`1048. **File names:** Descriptive, hyphenated, lowercase, <60 chars1059. **CDN:** Recommend for >50 images or global audience10610. **ImageObject schema:** For editorial/product/author photos107108### Output: IMAGE-OPTIMIZATION.md109Audit summary table, prioritized optimization list, recommendations by severity, corrected HTML snippets.
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