When re-platforming a multinational website, overlooking hreflang can be costly and have long-lasting consequences. The stakes are high: traffic drops, duplicate content issues, and users ending up on the wrong version of your site. In this post, we’ll explore why hreflang isn’t just a best practice—it’s mission-critical for maintaining international search visibility, optimizing user experience, and protecting your brand’s presence in global markets.
A strategic hreflang implementation can differentiate between a seamless transition and a global SEO disaster.
Why Replatforming Breaks Things
Every website refresh, CMS migration, or new market rollout introduces fundamental changes, especially in URLs. And while those changes may seem cosmetic or technical to developers, they represent something far more consequential to search engines:
The disappearance of a known entity.
Search engines don’t just score content; they associate signals of value (authority, backlinks, engagement, context) with the exact URL where that content resides. That URL is a unique identifier. It’s how the search engine remembers, scores, and retrieves your page.
So when the URL changes, even if the content and layout are identical, the search engine sees it as a brand-new page with no history.
It’s not just a change of address. It’s the introduction of a new, unverified identity with no prior reputation.
Yes, a well-executed 301 redirect can bridge that gap. It tells the search engine, “Hey, the old content is now here—please transfer its value.”
But here’s the catch: That transfer only happens when the old URL is revisited—either by a crawler or a user click.
The new URL has no inherited value until Googlebot reencounters the old URL and sees the redirect in place. It’s essentially invisible. If the redirect is missing, delayed, or incorrect, the connection is never made—and the new URL remains orphaned in Google’s index.
This is why redirect management is not optional during replatforming. It’s also why hreflang must be treated with the same precision—without it, Google has no idea which market-specific version of a page is meant for which audience.
Replatforming doesn’t just break URLs. It disrupts the web of trust and understanding search engines have built around your site—requiring a deliberate, well-communicated reintroduction.
Key Stats & Risks
- Websites may lose up to 85% of traffic after migration without proper planning.
- Post-migration, same-language pages may be flagged as duplicates.
- Implementing hreflang at launch minimizes duplication and accelerates indexing.
Migration and Replatforming Dynamics
Search engines use a wide range of signals to score and index content, most of which are tied to URLs. When URLs change, search engines treat the new pages as unknown entities with zero trust.
Redirects are the bridge. They signal that an old URL is now located at a new address, allowing Google and Bing to transfer relevance, authority, and link equity. Your SEO team’s insistence on getting redirects right stems from this very need.
Keep this concept of “reset to zero” in mind—it’s why hreflang and URL parity are so critical in global replatforming.
Speed of Reindexing
With replatforming, URL structures almost always change—sometimes due to platform constraints or local team preferences. This requires 100% of the new URLs to be discovered and indexed.
How Search Engines Discover New URLs
- Crawling the New Site
Googlebot may crawl the homepage and follow links to internal pages. But this can take time and may miss orphaned pages. - XML Sitemaps
Submitting updated XML sitemaps is a key best practice. These give Google a full inventory of new URLs, improving crawl efficiency. - Redirect Chains
When search engines revisit old URLs, a 301 redirect to the new URL transfers equity and triggers indexing. - Hreflang Tags (and XML Sitemaps)
Google has stated that encountering hreflang alternates prompts it to cross-validate and prioritize crawling.- On-page tags: Only discovered when the page is crawled.
- XML hreflang sitemaps: Immediately visible and can be flagged for special treatment.
- IndexNow (Bing)
For faster indexing with Bing, submitting via IndexNow can accelerate discovery.
Hreflang Cross-Validation Accelerates Crawling
Google has explicitly stated that when it encounters hreflang annotations either as tags in the page header or in XML sitemaps, it prioritizes cross-validating the linked alternates. This process triggers Googlebot to queue the referenced URLs for crawling in order to verify the reciprocal hreflang relationship. In practical terms, properly implemented hreflang annotations can expedite discovering and indexing new or migrated URLs across markets.
“When we detect a new hreflang link, we may schedule the linked URL for crawling so we can confirm the relationship is reciprocated.”
— Google Search Off The Record Podcast
This behavior is particularly beneficial during re-platforming or phased market migrations. If your new URLs are included in hreflang sitemaps—especially those referencing established URLs still in Google’s index—they are more likely to be crawled and trusted faster, reducing the “cold start” penalty that often comes with new pages.
This is one reason why hreflang XML sitemaps are strongly recommended during migrations: they allow Google to see the full set of international page relationships immediately without waiting to crawl each market individually.
Duplicate Content Challenge
Search engines penalize duplicate content to reduce indexing costs and improve user experience. Unfortunately, same-language pages across regions (e.g., US vs. Canada) are often flagged as duplicates if hreflang isn’t implemented correctly.
Case Study 1: 18-Market Relaunch
A brand relaunched 1,500 pages across 18 markets. Unique-language markets (e.g., Dutch, Polish, Italian, Japanese) reindexed well. However:
- Less than 10 English pages per market were indexed.
- French content ranked in Canada, but not in France, Belgium, or Switzerland.
- Germany was unindexed, while Austria was live.
Root cause: hreflang tags in the <head> were blocked by other scripts. Google couldn’t see them, so it treated the pages as duplicates. Deploying hreflang XML sitemaps began fixing the issue—10% of pages indexed within a week, 80% by month three.
Case Study 2: Hreflang Success Story
Another brand launched US English and German sites, using hreflang XML sitemaps from day one.
Result: 94% of pages indexed and showing impressions in Google Search Console within 10 days.
Multi-Platform and Multi-CMS Headaches
When different markets use different platforms (e.g., Salesforce in North America, Shopify in Europe, Sitecore in Asia), hreflang implementation becomes extremely difficult. These platforms typically:
- Do not communicate with each other, making automated hreflang tag generation impossible.
- Break hreflang clusters, especially when subdirectory structures or ccTLDs are inconsistently used.
Real-World Problem: Cross-Platform Indexing Fail
A company assumed hreflang would magically carry over during a replatforming. After launch:
- Local English and French pages failed to index.
- Google chose the US version for all same-language content.
- All non-English pages indexed correctly.
Diagnosis: No hreflang. Search Console reports flagged local English and French pages as “Duplicate – Google chose different canonical.”
This created cannibalization and fragmented visibility. ccTLDs (like .co.uk) are less prone to this issue, but if you’re using subdirectories like /us, hreflang is essential.
Getting It Right with Hreflang
Without hreflang, Google has no reason to treat similar pages in different regions as unique. For example:
- A US English version was flagged as a duplicate of UK/global English because no signals indicated a purpose difference.
- In another case, US content overrode German and French content in SERPs—hreflang wasn’t implemented.
Using tools like Hreflang Builder or other automation platforms can simplify the process:
- Map old URLs to new ones by market.
- Generate complete reciprocal hreflang clusters.
- Ensure proper A-B, B-C, A-C equivalencies.
Final Recommendations
To avoid disaster:
- Get redirects right – make sure old URLs properly redirect to new ones.
- Deploy hreflang at launch – don’t wait until post-launch to fix.
- Ensure full reciprocity – every page must reference its equivalents across markets.
Bonus: When to Get Involved
If you’re a global SEO manager, advocate being involved at the earliest stage of re-platforming planning. Ask:
- Will URLs change?
- What platforms are being used?
- Are we changing domains (e.g., from .com to .co.uk)?
- Who owns hreflang logic across systems?
Need Help?
If you need help auditing your current hreflang setup, preparing for a migration, or building a business case for doing it right, reach out. We’ve helped dozens of enterprise brands make seamless transitions with proper international setup—and we can help you, too.
