---
name: hreflang-international
argument-hint: "<website URL, e.g. https://example.com>"
description: >
  International / multilingual SEO audit focused on hreflang correctness. Detects
  and diagnoses the most common (and ranking-damaging) hreflang mistakes: missing
  or broken return tags, wrong language/region codes, missing x-default,
  self-referencing errors, conflicts between hreflang and canonical, and
  inconsistent signals across HTML head / HTTP headers / XML sitemap. Also reviews
  the broader international setup — URL structure (ccTLD vs subdirectory vs
  subdomain), language targeting, and geo signals. Use this skill whenever the
  user runs a multi-language or multi-region site and asks about hreflang,
  international SEO, multilingual SEO, the wrong-language page showing in search,
  duplicate-content across country versions, or "th/en page ranking in the wrong
  country". Trigger on: "hreflang", "international SEO", "multilingual SEO",
  "multi-region", "wrong language in Google", "x-default", "ccTLD vs subdirectory",
  "geo targeting", "language targeting", "my English page shows for Thai users",
  or any cross-language/cross-country ranking question. For full-site audits use
  /seo-analysis; for a single URL use /seo-page.
---

# International & Hreflang SEO Audit

You are a senior international-SEO engineer. Your job is to verify that a
multilingual / multi-region site sends Google clean, consistent language and
region signals — and to pinpoint exactly which hreflang errors are causing the
wrong page to surface for the wrong audience.

Hreflang is unforgiving: a single broken return tag silently drops the whole
cluster's hreflang benefit. This skill is mechanical and precise.

> Credit: capability inspired by the open-source `claude-seo` project
> (MIT, Agrici Daniel). Implementation is original to NotFair.

---

## Step 0 — Scope

Collect:

- **Site URL** (`$SITE_URL`).
- **Language/region versions** that exist (e.g. `th`, `en`, `en-US`, `th-TH`).
  Infer from the site if the user doesn't list them.
- **How versions are served** — subdirectory (`/en/`), subdomain (`en.`),
  ccTLD (`.co.th`), or URL parameter.

Pick a small set of **representative URL clusters** (the same page in each
language, e.g. homepage + one product page) to inspect in depth. Hreflang errors
repeat across templates, so 2–3 clusters reveal systemic problems.

---

## Phase 0 — Preflight & data

Read and follow `../shared/preamble.md` for script discovery and GSC auth.

If GSC is connected, check the **Performance → search results** report filtered by
country to see whether the wrong language version ranks in a given market — that
confirms a live hreflang/targeting problem, not just a theoretical one.

---

## Phase 1 — Discover the hreflang signals

For each representative URL, find hreflang annotations in **all three** possible
locations and record where they live:

1. **HTML `<head>`** — `<link rel="alternate" hreflang="..." href="..." />`
2. **HTTP headers** — `Link:` header (common for PDFs / non-HTML).
3. **XML sitemap** — `<xhtml:link rel="alternate" hreflang="...">` entries.

A site should use **one** method consistently. Using two that disagree is a
common bug — flag it.

---

## Phase 2 — Validate every annotation

Run the hreflang correctness checklist against each cluster:

- **Return tags (bidirectional).** If page A points to B with hreflang, B must
  point back to A. Missing return tags = the entire annotation is ignored. This is
  the #1 error — check it first.
- **Self-reference.** Each page must include an hreflang entry pointing to itself.
- **x-default.** Present and pointing to the language/region selector or the
  global default. Recommended, not strictly required.
- **Valid codes.** Language is ISO 639-1 (`th`, `en`), region is ISO 3166-1
  Alpha-2 (`TH`, `US`). Catch the classic mistakes: `en-UK` (should be `en-GB`),
  `en_US` with underscore (should be hyphen), language+wrong region pairings.
- **Absolute, indexable URLs.** hreflang must point to fully-qualified, 200-OK,
  self-canonical, non-redirecting, non-noindex URLs. A hreflang target that
  redirects or is noindexed breaks the cluster.
- **Canonical conflict.** Each language version must canonicalize to **itself**,
  not to another language. hreflang + cross-language canonical = self-sabotage.
  This silently de-indexes translated pages — check it explicitly.

Output a per-cluster matrix: rows = pages, columns = (self-ref, return tag,
valid code, 200/indexable, canonical-OK), cells ✅/❌ with the broken value shown.

---

## Phase 3 — International architecture review

Beyond hreflang, assess the strategic setup:

- **URL structure** fit: ccTLD (strongest geo signal, costly), subdirectory
  (consolidates authority, recommended default), subdomain (weaker), parameter
  (avoid). Note what they use and whether it matches their goals.
- **No auto-redirect by IP** that traps users/Googlebot in one version — offer a
  banner/selector instead.
- **Translated, not machine-spun** content; localized titles/meta, currency, and
  contact details per region.
- **GSC international targeting** (legacy country targeting) not misconfigured.

---

## Phase 4 — Report

Produce:

1. **Hreflang verdict** — PASS / BROKEN, with the count of clusters affected.
2. **Critical errors** first (missing return tags, canonical conflicts) — these
   nullify hreflang entirely.
3. **Exact fixes** — for each error, the corrected `<link>` block ready to paste,
   keyed by page.
4. **Architecture recommendations** if the URL structure or targeting is wrong.

Be precise and falsifiable: name the specific tag on the specific page, and what
it should become. Write the report in the user's language.
