When international teams audit AI search visibility, they may reach for the easiest shortcut: a single list of English prompts run across multiple country settings. It makes the spreadsheet clean, the headquarters review painless, and the cross-market charts easy to read.

It also hides the actual market.

Setting a search engine's location parameter to Tokyo or Seoul while feeding it English queries only shows results for English queries at that location setting. If your buyers search in Japanese or Korean, an English-only audit misses the source landscape those customers actually encounter. Before you commission a single translated page, you need to fix how you measure the results.

Same Country Setting, Completely Different Sources

A May 2026 study by Mingyue Zha and Ho-Chun Herbert Chang demonstrates how sharply the cited sources shift when you change the query language while holding the country setting fixed.

The researchers ran health queries on Google across several markets, comparing English prompts against local-language prompts from the exact same country setting:

  • Japan: Local sources made up 16.6% of citations for English queries, jumping to 57.5% for Japanese queries.
  • South Korea: Local citation share rose from 2.7% in English to 36.4% in Korean.
  • Malaysia and Singapore: Both markets showed the same directional shift toward local citations when queried in local languages.

Read those numbers carefully. They measure the share of citations classified as local—not the percentage of local businesses discovered—and the paper does not provide uncertainty intervals for these comparisons.

Furthermore, the authors defined "local" primarily by country-code top-level domains (ccTLDs). That is a tidy rule for an academic script, not a reliable map of real-world authority. A domestic hospital or software vendor on a `.com` domain gets misclassified as non-local under that rule, while a low-quality affiliate site on a country domain gets counted as local.

(Note: The paper also compared Google and Baidu across different countries and languages, which muddies platform effects with regional ones. Stick to the within-country Google numbers; that is where the useful signal lives for an audit brief.)

Build the Audit Around How Buyers Actually Ask

The first design question for any international audit is simple: whose searches are we trying to represent? Headquarters might discuss product categories in English, while local buyers frame the exact same problem using entirely different concepts in their own language.

Do not just run your English prompt list through machine translation. Literal translations can warp the service name, the local regulatory term, or the buyer's constraint—which means you end up testing a different question entirely.

Instead, define a small core of equivalent information needs, then have a native-speaking practitioner in each market write the phrasing a real customer would type.

When you run the tests, isolate your variables:

  • Hold the country setting fixed when testing language differences.
  • Hold the language fixed when testing location differences.

If you change both at once, you won't know whether a shift in citations came from the country setting or the phrasing. And always log the exact native wording alongside the English gloss in your final report so executives don't forget they are looking at two distinct query pools.

Distinguish Three Types of "Missing"

When your brand fails to show up in an AI Overview, lumping every miss into a single "0% visibility" bucket destroys diagnostic value. Break every observation down into three distinct outcomes:

  1. No AI Overview appeared at all. (This is a trigger question: does the engine even generate summaries for this topic in this language?)
  2. An Overview appeared, but cited zero local sources. (This is a source-mix question: does the engine favor global English repositories over domestic pages here?)
  3. An Overview appeared and cited local sources, just not yours. (This is a competitive question: who is winning the local slots, and why?)

Before drawing sweeping conclusions about a market, open the cited URLs and look at them. Domain-level tags lie. Check the page's actual language, the author, the backing institution, and whether it directly answers the prompt. And if your own local branch lives on a generic `.com` subfolder, make sure your tracking script explicitly recognizes it as a local asset—otherwise your own reporting rules will erase your wins.

Fix Your Measurement Before Buying Translations

Seeing a wide gap between English and local-language citations is a strong case for better monitoring. It is not an automatic mandate to translate your entire site tomorrow.

Zha and Chang's study is a single snapshot of health queries. It did not test what happens after a business translates its website, nor could it separate whether the search engine preferred global sources in English or simply lacked viable local pages to cite. What happens in medical queries will not automatically mirror B2B software, retail, or financial services.

Let your audit data dictate the next move. If local-language Overviews cite strong domestic competitors while ignoring your English pages, you have a clear content question to investigate. If the engine cites almost nothing local in any language, translation alone might not move the needle.

Start by recording the languages and locations your buyers actually use. A tidy global score built on English prompts doesn't give you international visibility—it just gives you a blind spot.