App Store cross-localization: using secondary locales to expand keyword coverage

Before moving on, let’s align on a few terms you’ll see throughout this article. These aren’t formal definitions—just the meanings that matter when you’re working with ASO in real store listings.

A locale: a specific language tied to a specific region. English (US), English (UK), Spanish (Mexico), and French (Canada) are all separate locales, even though some of them share the same base language.

App stores treat these locales as distinct sources of metadata, which directly affects how keywords are indexed.

Secondary locales—the additional locales available for your app alongside the primary one in a given market. In many cases, metadata from these locales is also indexed, giving you extra keyword coverage without changing your main listing.
This is the basis of most ASO multiple locales setups.

App cross-localization—the practice of using secondary locales to expand keyword reach within the same market. The app itself may remain unchanged, and the primary audience stays the same—the focus is on search visibility through additional indexed metadata.

Multiple app localization—refers to maintaining separate localized listings for different markets. In this article, it’s mentioned only to contrast it with App Store cross-localization, which operates within a single market.

These distinctions aren’t theoretical. Every decision that follows—what locales to open, what keywords to place where, and what results to expect—depends on them. 

If you mix up languages and locales, you’ll either overestimate the impact of localization or waste slots that could have driven real visibility.

With that foundation in place, we can look at the part that actually moves the needle: how indexing works on each platform and why the same locale setup produces very different results on the App Store and Google Play.

This is the point where most localization strategies break because teams assume both stores behave the same. They don’t.

On the App Store, metadata indexing is tied to locales, and in many territories more than one locale is indexed at the same time. That’s the entire reason app cross-localization exists.

In practical terms, this means that keywords placed in certain secondary locales can rank in the same country as your primary locale.

For example, in the US, the App Store indexes metadata not only from English (US), but also from several additional locales such as Spanish (Mexico), French, or Portuguese (Brazil), among others. 

Apple outlines how localized metadata is structured and managed in App Store Connect, which makes this behavior possible in practice.

What you get from this setup is simple: additional indexable metadata. Titles, subtitles, and keyword fields from secondary locales become additional indexing surfaces. That’s why ASO multiple locales on the App Store is a visibility tool first, not a translation task.

There are a few rules that matter here:

• Indexing is locale-scoped. Keywords and their combinations are formed within a single locale, and words from different locales don’t combine.

• Each locale should carry a distinct keyword role. Because keywords don’t combine across locales, splitting intent incorrectly reduces coverage. For example, if “coloring” is only in one locale and “for kids” is only in another, you won’t rank for “coloring for kids.”

This is why secondary locales are often filled with different keyword sets rather than mirrored content.

Google Play works on a completely different logic.

Here, localization is language-based, not country-based. A language version of your listing is shown to users based on their language settings, regardless of country. 

There is no concept of secondary locales contributing extra keyword space in the same way as on the App Store.

Adding more languages in Google Play helps you reach users who browse the store in those languages. It does not give you extra indexed fields for the same market. As a result, app cross-localization in the App Store sense simply doesn’t exist here.

In Google Play, multiple app localization is about relevance and conversion across different languages, not about stacking keyword slots.

If you treat both platforms the same, you’ll either expect results that never come or miss opportunities that are right in front of you. On the App Store, secondary locales are a lever for visibility.

On Google Play, they’re a lever for reach and usability.

Throughout this section, secondary locales are discussed strictly as an App Store indexing mechanism—not as a market expansion or localization strategy.

Secondary locales work because they solve a very specific ASO problem: limited keyword space.

In the App Store, every locale gives you its own set of metadata fields. When some of those locales are indexed in the same storefront, you effectively get more room to work with—without touching your primary listing. In ASO practice, this approach is commonly referred to as App Store cross-localization.
This makes secondary locales a visibility tool, not a localization exercise in the classic sense.

Important: a secondary locale isn’t an “empty container.” It can be user-facing in any storefront where that locale is available.

If you fill, say, Spanish (Mexico) with English keywords, Spanish-speaking users may see a mismatched listing. And if you later plan to scale into Mexico, that same localization will be shown there too—so treating it as keyword-only can cost you the market.

If the app is not available in a specific country, the secondary locale won’t be exposed to users there—allowing teams to use it purely for indexing without conversion risk.

This is a common setup when teams want to secure indexed locales without serving that market yet.

A safer approach is to keep visible text in secondary locales clean and intentional, and use the keyword field for extra coverage. This way, you get indexing benefits without breaking the listing experience for users who actually see that locale.

One controlled use case is multilingual search behavior within a single market. Users don’t always search in the “main” language of a storefront. In the US, for example, a meaningful share of searches happens in Spanish, even when the app itself is used in English.

This applies only when the secondary locale is meant to serve real users in another language, not when it’s used purely as indexable space.

In other cases, secondary locales are used strictly to expand keyword coverage in the primary language. Here, the goal isn’t to reach another language audience, but to distribute keyword clusters across additional indexed fields while keeping the visible listing coherent.

In both scenarios, the benefit comes from controlled expansion. Instead of forcing everything into a single title or keyword field, intent is spread across locales—one covers core, high-volume keywords, another supports variations and long-tail keywords that didn’t fit before.

That said, visibility alone isn’t the goal. More impressions help only when they stay relevant. When secondary locales are filled without a clear role—mixing languages or intent—conversion drops, and any ASO gains quickly evaporate.

Secondary locales are powerful, but they’re not universal. Whether they help or hurt depends on the state of the app and the problem you’re trying to solve.
They usually make sense when the core setup is already stable. The app has a clear value proposition, predictable conversion, and solid performance in its primary locale. At that point, adding secondary locales is about expanding reach, not fixing fundamentals. You’re layering visibility on top of something that already works.

A deeper look at when localization supports growth—and when it doesn’t—is covered in our guide on app localization best practices for real growth across markets.

They’re also effective when keyword space is genuinely tight. This happens often in competitive categories—utilities, wellness, finance—where relevant keywords outnumber available characters. Secondary locales give you room to cover adjacent intent without diluting the main message.

Another strong signal is a bilingual or multilingual audience inside a single market. The US, Canada, the UK, parts of Europe, and MENA are common examples. Users may browse and search in different languages while still expecting the same product experience. In those cases, secondary locales align naturally with real search behavior.

Where things go wrong is when secondary locales are used as a shortcut. If the primary listing struggles to convert, adding more traffic just amplifies the problem. Low relevance keywords bring impressions, not installs. The store algorithm notices. So do users.

They also don’t work well when teams treat locales as empty containers. Filling a locale “just because it’s available” usually leads to generic keywords, duplication, or off-target intent. At best, that wastes space. At worst, it drags down overall performance.

The rule of thumb is simple: secondary locales amplify whatever is already there. If the base is strong, they extend reach. If the base is weak, they expose it.

Opening every available locale rarely pays off. The goal isn’t volume—it’s alignment with real search behavior.

A good starting point is the audience you already have. Look at where installs come from and which languages users rely on inside your core markets. Bilingual and mixed-language regions are usually the strongest candidates. 

The US, Canada, the UK, and parts of Europe often justify secondary locales because users search in different languages while expecting the same app experience.

Competition is another useful signal. If leading apps in your category consistently use the same secondary locales, it’s rarely accidental. This usually points to proven keyword demand and established indexing patterns. Blind copying doesn’t work—but ignoring these signals does more harm than good.

Some ASO tools visualize indexed locales and inferred keyword overlap.

Capacity matters too. Every locale you open needs a clear role. If you can’t support keyword research, metadata updates, and performance tracking for a locale, it’s better left closed. A poorly maintained secondary locale quietly erodes ASO gains.

In practice, most effective setups start small. One or two carefully chosen secondary locales outperform five random ones almost every time.

Secondary locales aren’t an excuse to repeat the same keywords in a different language—or worse, in the same language. Repetition wastes space and rarely improves rankings.

Each locale needs its own keyword role. Primary locales usually carry core, high-intent terms. Secondary locales work better when they cover supporting intent: variations, synonyms, feature-specific queries, or long-tail searches that don’t fit into the main listing.

How keywords are selected depends on how the secondary locale is used.
If the goal is to capture searches in another language audience within the same storefront (for example, Spanish queries in the US), keywords should reflect how users phrase queries within that language audience within the same storefront, rather than being literal translations from the primary locale.

If the goal is to use a secondary locale purely as additional indexable space for the primary language, there is no need to research another market. In this case, the task is to distribute keyword clusters logically across locales and keep visible metadata coherent for users who may see that localization.

One important rule: keyword combinations are formed within a single locale. If two words never appear together in the same locale’s metadata, the store won’t combine them in search results.

The goal is balance—maximize coverage, keep relevance tight, and ensure each locale contributes something unique to visibility.

This is where strategy turns into real ASO results—or quietly breaks.

In the App Store, the primary locale should stay conversion-first. Titles and subtitles communicate value, not keyword ambition. Secondary locales give you flexibility, but they’re not a dumping ground. Even if a locale exists mainly for indexing, its visible text still has to look intentional.

Titles work best for the strongest, highest-intent keywords. Subtitles handle feature-level phrasing and supporting intent. The keyword field carries the rest—variations, long-tail queries, and edge cases that didn’t fit elsewhere.

Avoid aggressive language mixing in visible fields unless it reflects real user expectations. In the US, a Spanish subtitle can be natural. In other markets, it often looks off and hurts trust. If a secondary locale is opened mainly for ASO, keep experimentation inside the keyword field rather than the title.

As to Google Play, the rules are simpler and stricter. Each language version is fully user-facing and used globally. There’s no extra indexing surface to exploit, so metadata must always match the language and intent of users browsing in that language. 

If you need country- or keyword-specific listing variants, Google Play uses custom store listings—which is a different mechanism than secondary locales.
A simple quality check works well: if the listing feels confusing when read in isolation, the locale is doing damage—even if rankings go up.

Utility apps are the most active users of secondary locales. VPNs, cleaners, and scanner apps often separate intent across locales—one handles core protection keywords, another focuses on speed, privacy, or device-specific queries. The product stays the same, but search visibility widens.

Wellness apps take a softer approach. Sleep, meditation, and habit apps often use secondary locales to cover problem-driven searches—stress, anxiety, focus—where users phrase needs differently depending on language, even within the same market.

Finance apps tend to be conservative. Budgeting and expense-tracking apps usually reserve secondary locales for tightly related intent such as currency terms, spending categories, or regional wording. Broad or generic keywords here often hurt trust and conversion.

Across categories, the pattern is consistent: secondary locales work best when they extend an existing position, not when they try to invent a new one.

Secondary locales aren’t a trick and they’re not a shortcut. They’re an ASO lever that works only when the foundation is already solid.

Used correctly, they expand keyword coverage, reflect real search behavior, and increase visibility without bloating the main listing. Used carelessly, they inflate impressions, dilute relevance, and expose weak conversion.

At LoveMobile, we look at secondary locales through the lens of textual optimization for the App Store and Play Market. 

We analyze how additional locales affect keyword coverage, assess whether they align with real search patterns, and help teams understand where this approach can support organic growth—and where it won’t.

If you want to evaluate whether secondary locales make sense for your app, we can audit your current setup and outline the next ASO experiments. Contact our team.