使い方
- インストールコマンドをコピーし、自分の環境へ導入する前にソースを確認します。
- 必要なツール、認証情報、対応環境を原文で確認します。
- 入力と成果物を指定し、出力を資料と照合します。
npx skills add https://github.com/kostja94/marketing-skills --skill canonical-tag開始前の確認
- 導入にはモデル契約、API枠、ファイルへのアクセス許可は含まれません。
- スター数や導入数は活動の指標であり、独立した品質・安全性試験ではありません。
見出し、例、コード、表、リンク、参照画像を含む原文を表示しています。
SEO Technical: Canonical
Guides canonical tag configuration to consolidate duplicate content and declare preferred URLs.
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)
- Duplicate site versions: HTTPS vs HTTP; www vs non-www; trailing slash (/page vs /page/) — choose one, 301 redirect others
- Duplicate content: Canonical tags; consolidate and 301 to preferred URL
- HTTPS: SSL/TLS; secure connection; ranking signal since 2014
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:
- Site URL: Base domain
- Duplicate scenarios: Multi-language, query params, pagination, alternate URLs
- Framework: Next.js, React, static, etc.
Canonicalization Methods (Choose by Scenario)
| Method | When | Strength |
|---|---|---|
| 301 redirect | Preferred; server can redirect | Strongest — permanent redirect |
| Canonical tag | Cannot redirect (e.g. params, pagination) | Strong — HTML signal |
| robots.txt | Block non-canonical paths | Weak — advisory only |
Use 301 for HTTP→HTTPS, www variants, trailing slash. Use canonical for params, pagination, UTM.
HTTPS & Security
HTTPS is a ranking signal (Google, 2014). Users and crawlers should access only the HTTPS version.
| Requirement | Action |
|---|---|
| SSL/TLS certificate | Install valid certificate; use Let's Encrypt for free |
| 301 redirect | HTTP → HTTPS; all HTTP requests redirect to HTTPS |
| Mixed content | No HTTP resources on HTTPS pages; fix mixed content warnings |
| HSTS | Optional; Strict-Transport-Security header for repeat visitors |
WWW vs non-WWW: Choose one preferred version; 301 redirect the other. See canonical rules above.
When to Use Canonical
- Multi-language: Each language version has its own canonical; use hreflang with canonical
- Same content, multiple URLs: Params, pagination, tracking params, www vs non-www, trailing slash (/page vs /page/)
- Self-referencing: Canonical should point to self or the preferred version
- Avoid chain canonical: A→B→C is invalid
Rules
| Rule | Note |
|---|---|
| Absolute URL | Include https:// |
| Consistency | Must match current page URL or the chosen preferred version |
| No chains | A→B→C is invalid |
Implementation Patterns
Next.js (metadata)
export const metadata = {
alternates: {
canonical: "https://example.com/page-slug",
languages: {
zh: "https://example.com/zh/page-slug",
en: "https://example.com/page-slug",
"x-default": "https://example.com/page-slug",
},
},
};HTML (generic)
<link rel="canonical" href="https://example.com/page-slug" />Server Redirects (301)
Apache (.htaccess):
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]Nginx:
return 301 https://$host$request_uri;Relationship to Other Technical SEO
- Sitemap: URLs in sitemap should match canonical
- IndexNow: Submit canonical URLs
Output Format
- Canonical URL for each page type
- Implementation (metadata or HTML)
- Multi-language setup if applicable
- References: Alignify URL optimization; Google Canonical
Related Skills
- url-structure: URL hierarchy and format; canonical handles duplicate variants (HTTPS, www, trailing slash)
- localization-strategy: hreflang + canonical for multi-language
- xml-sitemap: Sitemap URLs should match canonical
- indexnow: Submit canonical URLs
- google-search-console: Find duplicate content in Coverage report
- indexing: Resolve indexing issues
- site-crawlability: Crawl budget; redirect chains; canonical reduces duplicate crawl waste
