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

Project context: Read root contextus.md when present and load only the modules relevant to this task. Without Contextus, use available project material or user-provided facts and ask for missing information; do not create a parallel context system.

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

Precondition: Does the site need a sitemap?

Before generating, assess whether a sitemap is warranted. A sitemap is most valuable when:

• Large site (hundreds+ pages) or new site with few backlinks
• Deep or orphaned pages that internal links don't reach well
• Rich media (images, videos, news) needing extension metadata
• GSC shows growing "Discovered – not indexed" or "Not discovered" counts

Small sites (< 50 pages) with strong internal linking may not strictly need one, but creating a sitemap has near-zero cost and provides future-proof infrastructure. If in doubt, err on the side of creating.

1. Protocol Essentials

2. Field Requirements

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); centralizes hreflang management.

Rules:

• Every language version must link to ALL others, including itself (self-reference).
• Include x-default pointing to default locale.
• Use xmlns:xhtml="http://www.w3.org/1999/xhtml" namespace.
• <loc> typically uses default-locale (clean) URL; x-default points there too.

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
        xmlns:xhtml="http://www.w3.org/1999/xhtml">
  <url>
    <loc>https://example.com/page</loc>
    <xhtml:link rel="alternate" hreflang="en" href="https://example.com/page" />
    <xhtml:link rel="alternate" hreflang="zh" href="https://example.com/zh/page" />
    <xhtml:link rel="alternate" hreflang="x-default" href="https://example.com/page" />
  </url>
</urlset>

List all language sitemaps in sitemap index; include in robots.txt.

4. Implementation

Route Exclusion

• If the project has i18n / middleware redirects, exclude sitemap paths to avoid redirect.
• Example (Next.js matcher): '/((?!api|_next|sitemap|sitemap-index|.*\\..*).*)'.

5. Page Scope

Include

• Home: /
• Locale/region home pages (e.g. /zh, /en)
• All indexable content pages, list pages, category pages

Exclude

• /api/*, /admin/*, /_next/*
• Static assets (images, JS, CSS, etc.). For image discovery, use image sitemap extension—see image-optimization. For video discovery, use video sitemap extension—see video-optimization
• Login, admin, drafts, and other pages not intended for indexing