International SEO
Hreflang and Canonical Checks Before a Domain Launch
Check that translated pages point to the live domain, canonical to the right URL and link back to their language equivalents.
By Starry Research Labs · Published and reviewed
What should each translated page point to?
Each language page needs a preferred public URL. Its canonical should normally point to that language version, while hreflang connects equivalent translations. Check the actual tags in the delivered HTML after moving from a preview domain.
Keep a short mapping of language, old URL and final URL. For this website, the language paths are /, /zh-hant and /en. They keep their paths on starryresearchlabs.com.
How do you check return links?
Read a page's language links, open each translated equivalent and check that it links back. A one-way relationship can leave an incomplete language cluster. Also check whether a target redirects somewhere unexpected or returns an error.
Our checker examines up to six alternate URLs from one page. If your site has more languages, check the remaining targets separately. An annotation in a sitemap or added only after JavaScript runs falls outside this HTML check.
What goes wrong with a preview-domain canonical?
A production page that names a preview URL as its preferred version sends an unwanted canonical signal. On our pre-release audit, all three language pages still named the Vercel deployment domain. The pages loaded normally, so an availability check alone missed the problem.
Fix the base URL, review the delivered canonical and language links, then inspect Google's selected canonical in Search Console once recrawling has happened. A corrected tag alone does not prove Google has adopted the preference.
What belongs in the launch check?
Check every language URL on the final domain. Keep the source HTML and the final destination of any redirects as evidence.
- A successful HTML response at the intended language URL.
- A canonical on the correct host and language path.
- Language links to equivalent pages, with return links.
- A sitemap containing the preferred URLs.
Sources and method
External references were reviewed for this guide. Examples and tool workflows are our own. The launch audit records our public website observations, with no ranking or citation claim.