Should I use subdomains (en.example.com) or paths (/en) for i18n?

Both can work. Path-based i18n (/en) is often the most practical: it keeps authority on one domain, is simpler to deploy, and makes internal linking consistent. Subdomains can isolate sites but usually require more maintenance and signal consolidation.

Do I need hreflang on every page?

If a page has language variants, it’s best to add hreflang on each variant and ensure they reference each other (reciprocal). Missing or inconsistent tags make pairing unreliable.

Can different languages canonicalize to one URL?

Usually no. Each language version should be self-canonical, and hreflang should be used to declare language alternates.

International SEO (i18n) Playbook

Done right, multilingual SEO unlocks global search demand. Done wrong, it becomes duplicate content, wrong-language rankings, and indexing chaos. This guide covers URL structure, hreflang, canonicals, and Cloudflare Pages gotchas.

1) URL structure: path prefixes (/en) are a practical default

Consolidated authority: one domain compounds signals faster
Simpler deployments: static output works great on Cloudflare Pages
Consistent internal linking: tutorials ↔ glossary ↔ tools can mirror structure

The key is consistency: each locale must have its own URL, its own canonical, and hreflang mappings.

2) hreflang: pair language variants correctly

hreflang is not a ranking boost. It helps search engines serve the right language/region page to the right user and reduces wrong-language rankings.

html

<link rel="alternate" hreflang="zh-TW" href="https://seo.lucas-futures.com/tools" />
<link rel="alternate" hreflang="en" href="https://seo.lucas-futures.com/en/tools" />
<link rel="alternate" hreflang="x-default" href="https://seo.lucas-futures.com/en/tools" />

Self-referential: include the current page in the hreflang set
Reciprocal: if A points to B, B must point back to A
x-default: your fallback when no language matches

Glossary: hreflang

3) Canonicals: self-canonical for each locale

A common mistake is cross-language canonicalization (English canonical to Chinese, or vice versa). That turns language variants into duplicates and usually collapses indexing to one version.

html

<!-- zh-TW page -->
<link rel="canonical" href="https://seo.lucas-futures.com/glossary/seo" />

<!-- en page -->
<link rel="canonical" href="https://seo.lucas-futures.com/en/glossary/seo" />

Glossary: canonical URL, duplicate content

4) Content quality: don’t turn i18n into thin content

Don’t translate only navigation: translate key pages (home/tools/tutorials/glossary)
Avoid low-quality machine translation: thin pages dilute site-wide quality signals
Keep structure consistent: summaries, steps and FAQs are great for AEO

5) Cloudflare Pages gotchas (important)

If you prerender per-route HTML, avoid SPA catch-all rewrites that override route files. Otherwise every path may return the same HTML, breaking per-page OG and SEO.

Keep `dist/**/index.html` per route
Ensure <html lang> is correct (zh-TW / en)
Include all locale URLs in your sitemap (this site generates it automatically)

Glossary Free tools Technical SEO

FAQ

Common multilingual SEO questions.