Localization and multi-market ASO
App store localization means adapting metadata and creative per storefront so each market's users find and choose your app in their own language. It is not translation: keyword demand differs by market, so a localized listing starts with fresh research in the target language, not a translated word list. Apple adds a structural benefit — each filled locale gives another indexed name, subtitle and 100-character keyword field, and some storefronts index a second locale, so English (UK) expands coverage even in the US. Prioritize markets by organic impressions and revenue per install, and localize metadata and screenshot captions before the app itself.
Key takeaways
- Translation is not localization — run keyword research natively in each target language.
- Every filled Apple locale adds another indexed name, subtitle and keyword field.
- Some storefronts index a second locale, so English (UK) or (AU) can extend US keyword coverage.
- Localize screenshot captions before localizing the app itself; captions gate the install decision.
- Pick markets from your existing impression and revenue data, not from market-size league tables.
Choosing which markets to localize
- Start with storefronts that already produce organic impressions without any localization — demand exists there already.
- Weight by revenue per install rather than population; a smaller market with strong monetisation usually pays back faster.
- Check competitive density in the target language; an underserved language is a cheaper win than a crowded one.
- Confirm you can support the market — reviews in a language nobody on the team reads become a rating problem.
How locale coverage works on each store
| Aspect | App Store | Google Play |
|---|---|---|
| Indexed fields per locale | Name, subtitle, keyword field | Title, short description, full description |
| Secondary locale indexing | Yes in several storefronts, e.g. en-GB in the US | No equivalent |
| Creative per locale | Screenshots and video per locale | Screenshots and video per locale |
| Fallback | Falls back to the primary locale | Falls back to the default language |
The localization process
- 1
Native keyword research
Build a seed list in the target language from store autocomplete and local competitors, never from a translated English list.
- 2
Metadata drafting
Write name, subtitle and keyword field — or title and descriptions — to the local character budget; some languages need far fewer characters to say the same thing.
- 3
Caption localization
Translate and re-typeset screenshot captions. Longer languages such as German frequently break a layout designed for English.
- 4
Cultural review
Have a native speaker check imagery, colour and claims, not just grammar.
- 5
Measure per storefront
Track impressions, conversion and revenue per install by locale so each market can be judged on its own return.
Worked example: three markets, three different results
A meditation app localized into German, Japanese and Brazilian Portuguese in the same release, using the same process for all three, and got three different outcomes — which is the useful part of the story, because the variable was the market rather than the effort.
German gained the least. The audience has high English tolerance and the category vocabulary is largely borrowed, so the translated listing competed against the English one for much the same searches. Brazilian Portuguese gained the most: English tolerance is lower, the local competitive set was thinner, and the translated metadata found demand nobody was serving. Japanese sat between the two and only worked after the second pass, because the first version had been translated rather than rewritten and used the formal register a wellness app should avoid.
The lesson is not that localization works or does not. It is that a straight translation captures the smallest share of the available gain, and the difference between markets is large enough that ranking them before you start decides most of the return.
Where localization projects go wrong
The failures are rarely linguistic. They are process failures:
- Machine-translating metadata, which produces grammatical copy built on the wrong keywords.
- Translating the keyword field instead of researching the local terms, which are frequently different words rather than translations.
- Localizing text and leaving screenshots in English, so the listing reads as half-abandoned.
- Ignoring locale variants that share a language but not a vocabulary, such as Latin American and European Spanish.
- Localizing everywhere at once instead of proving the return on two markets first.
- Letting localized listings go stale after the next English release, which reintroduces the mismatch you paid to remove.
Frequently asked questions
Which languages should I localize my app store listing into first?
Start with the storefronts already generating organic impressions, weighted by revenue per install. For most Western apps that is some combination of German, French, Spanish, Japanese and Korean.
Do I need to localize the app itself, or just the store listing?
Localizing the listing alone can be tested cheaply, but if the app remains English, ratings in that market will suffer. Treat listing-only localization as a market test, not an end state.
Does adding English (UK) help a US app?
On the App Store, yes. Several storefronts index a second English locale, so filling English (UK) or English (Australia) adds another 100-character keyword field that counts in the US.
appXL Research
App Store Optimization Research Team
The appXL research team analyzes App Store and Google Play ranking data across the apps our agent manages, and publishes what it finds.