What Is Cross Localization in App Store for ASO?

1. What is cross localization in the App Store?

Cross localization in App Store for ASO is a strategy where Apple indexes metadata from more than one locale for a single country storefront. Each store (e.g. US, UK, Germany) has a primary language. You can add one or more secondary locales in App Store Connect and fill their title, subtitle, and keyword field. Apple then indexes both the primary and secondary locale metadata for that store, so your app can rank for keywords from both—without changing your app code or shipping in-app translations.

So cross localization is not the same as "translating your app for Spain and Mexico." It is about adding an extra set of metadata (often in another language or a variant of the same language) that the store already supports for that territory, so you get more keyword coverage in that one store.

2. How does cross localization work?

In App Store Connect, each app version has a primary language and optional additional locales per territory. For example, the US App Store can index both English (US) and Spanish (Mexico) as secondary. If you set Spanish (Mexico) as a secondary locale for the US store and fill in title, subtitle, and keywords there, those terms are indexed alongside your English (US) metadata. Users still see your primary listing by default; the secondary locale is used for search indexing.

Not every territory supports the same secondary locales. Apple defines which languages are available per store. The practical step is to add a secondary locale that is relevant to your audience or that gives you a second 100-character keyword field (and extra title/subtitle space) for the same store.

• You add a secondary locale in App Store Connect for a given territory.
• You fill title, subtitle, and keyword field for that locale.
• Apple indexes both primary and secondary metadata for search in that store.
• No app update or in-app localization is required.

3. Why cross localization matters for ASO

The main ASO benefit is more keyword coverage per store. You are limited to one 100-character keyword field per locale. By adding a secondary locale, you effectively get a second set of metadata indexed for the same storefront—so you can target more search terms without changing your app. That can help you rank for long-tail or alternate phrasings that don’t fit in your primary keyword field.

It is a metadata-only lever: no engineering, no new builds, no in-app strings. As long as you use relevant, non-spammy keywords and follow store guidelines, cross localization is a supported use of the platform.

4. Best practices for cross localization

Use only relevant keywords in the secondary locale. Terms that don’t match user intent can hurt conversion when users land on your page from a query that doesn’t match your app. Avoid stuffing or duplicate keywords across primary and secondary: each word is typically counted once, and duplication doesn’t add value. Use commas between keywords to maximize combinations. Don’t add secondary locales just to "fill" them—only use locales that can realistically drive discovery in that store.

• Choose a secondary locale that is supported for the store and relevant to your audience or keyword strategy.
• Fill title, subtitle, and keywords with terms that are not already covered in your primary locale.
• Avoid repeating the same keywords in both locales; focus on additional, relevant terms.
• Use comma-separated keywords to allow more combinations.
• Don’t add empty or irrelevant locales just to have more fields.

5. Cross localization vs. full app localization

Cross localization is about metadata and search indexing for one store. Full localization is about translating your app and its listing for multiple storefronts (e.g. US, Spain, Mexico, Germany) so that users in each country see and search in their language. Both can be part of a broader ASO and international strategy: use cross localization to expand keyword coverage in key stores, and use full localization to grow in new territories with localized product pages and in-app experience.

6. Bottom line

Cross localization in App Store for ASO means using secondary locale metadata so that Apple indexes more keywords for the same country store. It’s a metadata-only tactic that can improve search visibility without code changes. Use it with relevant, non-duplicate keywords and only for locales that make sense for your app and audience. For ASO audits and store metadata strategy, Asset-Box offers keyword and localization support.

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