How a Single Comment About hreflang and Redirects nearly led to catastrophic consequences during a Global Site Migration
Early Monday morning, I saw an email update from Barry Schwartz from Search Engine Roundtable documenting Search Marketer’s question to Google’s John Mueller on Mastodon about the “need for hreflang tags needing to point to 200 status pages. I rolled my eyes and moved on, knowing if I read the article, there was a good chance it would ruin my day, but like a car wreck, I had to look.
When I first read the post, I applied my critical thinker’s interpretation …
What I think John Mueller Said:
“If most of the hreflang annotations are ok, that’s fine. It’s more a matter of how the reporting looks than it causing problems.”
Why this interpretation?
John’s comment addresses Matt’s specific situation—probably where a few hreflang annotations point to 301s, but most are functioning. John’s point is: “Don’t panic if a few are broken; the world won’t end.”
This isn’t wrong in isolation. But here’s the problem:
Many people apply isolated statements like this universally, often with unintended consequences.
In our Understanding & Fixing Hreflang Common Errors course, I have dozens of screen captures of various interpretations and extrapolations of Google responses by multiple SEO Gurus and the actual and potential damage they can cause. Today, there were no comments on either Mastodon’s or Barry’s post, so I thought maybe we were safe from the TL;DR crowd.
Then, today, after lunch, I received the SEO’s interpretation that I feared. He sent a screen capture of the post and indicated that they “were correct. ” They did not need to fix the mapping because Google said they can “ Understand the redirects,” so there was no need to fix them immediately. That is NOT what John said, but that is how it was interpreted.
Since I no longer own Hreflang Builder, I thanked him for the update and responded, “Sounds like you have a plan.” For background, I had previously spoken to this SEO and his agency about non-recipricating hreflang elements because they added a regional ID to the SKU Hreflang Builder used to map the pages automatically. The auto mapping was breaking because there was no rule to let the system know that this new format was equal to the old format. I told him how he could set the logic to map them, but he felt that would be too much work and felt that Google should be able to figure it out. The difference was that this was “tens of thousands of pages”; they expected this to happen magically.
Site Note: Hreflang Builder has a migration mapping element. A user can import a file with the Old URL and the New URL, and anything mapped to the old URL is mapped to the new URL. It is a very powerful function, but again, the agency did not want to utilize it.
Why You Should Still Fix hreflang 301s
1. Broken Reciprocity = Broken Implementation
Google’s documentation clearly states that hreflang must be reciprocated — meaning page A references page B, and B references back to A.
The reciprocation chain is broken if A links to B, but B 301s to C (and C doesn’t reference back). Google may try to resolve it, but it is not guaranteed. This alone is enough to reject the idea that ALL 301s in hreflang tags are “fine.”
2. Google Doesn’t Always “Figure It Out”
Redirects often occur during migrations, domain consolidation, or CMS changes—exactly the scenarios where precision matters most. Relying on Google to infer relationships across redirects increases risk during already fragile transitions. Google might get it right eventually, but in business-critical environments, “eventually” is too late.
In my vast hreflang experience, I have worked with numerous companies that didn’t prioritize hreflang cleanup during a migration, which resulted in geo-targeting misalignment, loss of signals, or delayed indexing of intended alternates. In two recent cases, the company deployed a new market and changed the URL structures in Europe.
They did not update their hreflang and the new market pages; most English market pages were not indexed. Their Dev Ops Manager and part-time SEO both “assumed or “hoped” Google would figure it out, as they did not have the time or budget to update hreflang. A few months later, they contacted me. They showed me the GSC for the UK and Ireland markets, and Google flagged 100% of the pages as duplicate Canonicals, referencing the unchanged US site as the preferred page.
When Google went to index the new pages, they were viewed as mirror images of the existing US versions, and Google did not need to index them. This is the very reason why hreflang elements are critical for migrations.
Not believing Google’s stupidity, they begrudgingly did a test hreflang XML sitemap for a few key pages, and in less than a week, they were ALL indexed and ranking. This was proof enough that Google was not figuring it out, and if they wanted traffic to those market pages, they would need to make time to clean up their hreflang.
3. Marauding Black Holes and Localization Icebergs
If you are still unsure that they should be fixed, take a moment to read my recap of the Search Off the Record Podcast discussion with Allan Scott from Google’s Dupes Team or listen to it yourself. Allan talks about Maruading Black Holes formed when redirects are not managed and the Localization Iceberg complexities when hreflang signals are not set correctly. Adam specifically mentions at [06:11] “A significant challenge for the Dupes Team is applying weighting logic to detect duplicates, especially when a webmaster sends conflicting signals.”
Final Thoughts: Context Is Critical—Especially in SEO
In the ever-evolving landscape of SEO, Google’s guidance often comes in nuanced statements that require careful interpretation. While extracting broad strategies from brief comments is tempting, doing so without full context can lead to significant missteps.
Take, for example, the discussion around hreflang tags and 301 redirects. A well-intentioned remark suggesting that Google can “figure it out” might seem reassuring. However, applying this notion universally, especially during critical processes like site migrations, can disrupt the delicate balance of international SEO efforts.
Google’s own documentation emphasizes the importance of reciprocal hreflang annotations and accurate implementation to ensure proper indexing and user targeting. Relying on Google’s algorithms to compensate for oversights may sometimes work, but it’s not a substitute for diligent SEO practices.
While Google’s insights are invaluable, they should be integrated into your strategy with a comprehensive understanding of the specific context and technical requirements. Avoid the pitfalls of overgeneralization by critically assessing how each piece of advice aligns with your unique SEO objectives.
