nextjs-i18n-seo

Next.js i18n SEO Fix

Multilingual Next.js sites commonly ship with a crawlability-killing bug: locale redirects that use 307 Temporary instead of 301 Permanent. This means Googlebot never transfers PageRank to the actual indexed URL. Fix this first — it's a one-line change with immediate impact.

The Core Problem

When a user (or Googlebot) hits /hexagrams/14, Next.js middleware redirects to /en/hexagrams/14. The default NextResponse.redirect(url) issues a 307 Temporary Redirect. Google does not transfer PageRank on 307s. Result: any backlink to the clean URL is wasted.

Pages Router doesn't have this problem because getStaticPaths generates pages at their final URL with no redirect hop.

---

Phase 1: Audit the Site

1. Check the redirect status code

curl -I https://example.com/some-page
# Look for: Location: and HTTP/2 301 vs 307

2. Check robots.txt

https://example.com/robots.txt

• All paths should be allowed (or only /api/ blocked)
• Sitemap URL must be listed

3. Check the sitemap

https://example.com/sitemap.xml

• Are all pages listed with their final (locale-prefixed) URL?
• Are alternates.languages hreflang entries present?

4. Inspect the middleware

Look for NextResponse.redirect(url) — if no status code is passed, it's a 307.

---

Phase 2: Fix the 307 → 301 Bug

File: src/middleware.ts (or middleware.ts at root)

// ❌ BEFORE — issues 307 Temporary Redirect
const response = NextResponse.redirect(newUrl);

// ✅ AFTER — issues 301 Permanent Redirect (passes PageRank)
const response = NextResponse.redirect(newUrl, 301);

Also fix any locale alias redirects (e.g. zh-hans → zh-CN) the same way — they should already be 301 if added later, but verify.

Commit message:

fix: change locale redirect from 307 to 301 for SEO PageRank transfer

---

Phase 3 (Optional but Recommended): No-Prefix Default Locale

The locale prefix (/en/hexagrams/14) adds an extra path segment vs. /hexagrams/14. For English-first sites, removing the prefix from the default locale gives cleaner URLs and eliminates the redirect entirely for the primary language.