Xml Sitemap

# SEO Technical: Sitemap

Guides sitemap creation, auditing, and optimization for search engine discovery.

**When invoking**: On **first use**, if helpful, open with 1–2 sentences on what this skill covers and why it matters, then provide the main output. On **subsequent use** or when the user asks to skip, go directly to the main output.

## Scope (Technical SEO)

- **Sitemap**: Create XML sitemap; submit to Google Search Console
- **URL discovery**: Help search engines find pages; especially important for large sites or poor internal linking

## Task

Generate an XML Sitemap that complies with the sitemaps.org protocol from the project's page list, and declare it in robots.txt.

## Initial Assessment

**Check for project context first:** If `.claude/project-context.md` or `.cursor/project-context.md` exists, read it for site URL and page structure.

Identify:
1. **Site URL**: Base domain (e.g., `https://example.com`)
2. **URL count**: Total indexable pages (single sitemap vs. sitemap index)
3. **Data source**: Static config, CMS, file system, or hybrid

## 1. Protocol Essentials

| Item | Spec |
|------|------|
| Single sitemap limit | 50,000 URLs, 50MB (uncompressed) |
| Sitemap index | When exceeding limit, split and have main index reference sub-sitemaps |
| Encoding | UTF-8 |
| URL format | Full URL, same host, include `https://` |
| Required tags | `<loc>` |
| Optional tags | `<lastmod>`, `<changefreq>`, `<priority>` |

## 2. Field Requirements

| Field | Description | Recommendation |
|-------|--------------|---------------|
| url | Full URL | `https://example.com/path` |
| lastModified | Page last modified time | Use page metadata, ISO 8601; use `YYYY-MM-DD` or omit when no data |
| changeFrequency | Update frequency | Home `daily`, list pages `weekly`, content pages `monthly` |
| priority | Relative importance | Home 1.0, aggregate pages 0.9, content pages 0.7–0.8, others 0.5–0.6 |

### lastmod (Critical)

- **Must be accurate**: Reflect actual page modification time, not sitemap generation time. Google requires verifiability; Bing reports ~18% of sitemaps have incorrect lastmod values.
- **Format**: W3C Datetime (`YYYY-MM-DD` or `YYYY-MM-DDTHH:MM:SS+TZD`), e.g. `2025-01-15`, `2025-01-15T14:30:00+08:00`.
- **Avoid**: Using `new Date()` for lastmod—causes all URLs to share the same timestamp; search engines may ignore.
- **Apply when**: Content updates, structured data changes, or important link changes.

### changefreq / priority

- **changefreq**: Hints only; does not directly determine crawl frequency. Values: `always`, `hourly`, `daily`, `weekly`, `monthly`, `yearly`, `never`.
- **priority**: 0.0–1.0; **does not affect ranking**; set higher for important pages; avoid identical values for all.

## 3. Architecture & Split

### Single Sitemap

- When URLs >50,000, generate `/sitemap.xml` directly.

### Sitemap Index (Multiple Sub-sitemaps)

- When exceeding limit, split by type or language; main index references sub-sitemaps.
- Example splits: `/sitemap/posts.xml`, `/sitemap/pages.xml`, `/sitemap/zh.xml`, `/sitemap/en.xml`.
- Main index outputs `/sitemap.xml` or `/sitemap-index.xml`, each entry as `<sitemap><loc>...</loc></sitemap>`.

### Multilingual Sites

- Split by locale: `/sitemap/zh.xml`, `/sitemap/en.xml`.
- Or by content type + language: `/sitemap/zh-posts.xml`, `/sitemap/en-posts.xml`.

### Multi-Language Sitemap (hreflang in Sitemap)

For multilingual sites, add `xhtml:link` hreflang alternates inside each `<url>` entry. **Recommended for large sites** (100+ multilingual pages); centralize