Best Languages to Localize Your iOS App Into
You can't localize into every language at once. Even if you could, you shouldn't — the returns vary wildly by market. Japanese localization for a productivity app might pay for itself in a week. Thai localization for the same app might take six months. The question isn't whether to localize, but where to start.
This guide ranks languages by their actual revenue opportunity for iOS developers, based on App Store revenue data, iOS market share, user willingness to pay, and competition levels. We've organized them into three tiers to help you allocate your localization budget where it matters most.
How We Ranked These Languages
Four factors determine a language's localization ROI:
- App Store revenue share — how much money flows through that market's App Store
- iOS market share — what percentage of smartphone users are on iPhone
- Average revenue per user (ARPU) — how much each user is worth
- Localization competition — how many competing apps have already localized, which affects how much low-hanging fruit remains
A market with massive revenue but 90% of apps already localized (like the US) offers less incremental opportunity than a smaller market where most foreign apps haven't bothered. The latest App Store statistics paint a clear picture of where the money flows.
Tier 1: Must-Have Languages
These languages represent the highest-confidence localization investments. Most iOS apps will see positive ROI from these markets regardless of category.
Japanese (ja)
Japan is the single most valuable localization target for most iOS apps. It's the second-largest App Store market by revenue, with iOS commanding roughly 65% smartphone market share — the highest of any major economy outside the US. Japanese users have the highest ARPU globally for mobile apps and a strong cultural preference for paying for quality software rather than tolerating ads.
The catch: Japanese localization demands precision. Machine translation without cultural review will actively hurt you. Keigo (honorific language) matters in professional and finance apps. Katakana usage for foreign loanwords follows specific conventions that direct translation misses. But get it right, and Japan is often an app's most profitable non-English market.
Expected download increase: 150-300% in the Japanese App Store after quality localization.
Simplified Chinese (zh-Hans)
China is the world's largest App Store market by downloads and second by revenue. The numbers are staggering: over 250 million active iOS devices. But the Chinese market comes with unique considerations. Many app categories require an ICP license. Some features (like social networking or streaming) face regulatory restrictions. And Chinese users have strong preferences for local app aesthetics — information-dense interfaces, prominent social proof, and feature-forward screenshots.
If your app can operate in China, localizing into Simplified Chinese is a no-brainer. Even if you can't serve mainland China, Simplified Chinese covers Singapore's Chinese-speaking population and is increasingly used by Chinese-speaking users worldwide.
Expected download increase: 200-500% in the Chinese App Store after quality localization.
German (de)
Germany is the largest economy in Europe and the third-largest App Store market by revenue globally. German users are willing to pay for software, particularly for productivity, business, and utility apps. iOS holds approximately 30% market share in Germany, but that 30% represents a disproportionately high-spending demographic.
German localization is relatively straightforward linguistically (compared to CJK languages), but there are details that matter: formal "Sie" vs. informal "du" (most apps now use "du" but B2B tools may need "Sie"), compound nouns that can blow character limits, and strict privacy expectations influenced by GDPR culture. German users are also notably intolerant of poor localization — a single awkward phrase can trigger a 1-star review.
Expected download increase: 80-150% in the German App Store after localization.
French (fr)
French covers not just France (the fourth-largest European App Store market) but also Belgium, Switzerland, Canada (Quebec), and large parts of Africa. This linguistic reach makes French one of the highest-coverage single-language investments you can make. France's iOS market is strong in subscriptions and in-app purchases, particularly for lifestyle, health, and education apps.
One important nuance: French for France and French for Canada differ in vocabulary and idiom, though mutual intelligibility is high. Apple treats them as separate localizations (fr-FR and fr-CA), so you can tailor each if budget permits. At minimum, standard French (fr-FR) will serve all French-speaking markets acceptably.
Expected download increase: 70-130% across French-speaking App Store markets.
Korean (ko)
South Korea punches far above its population weight in App Store revenue. With about 52 million people, it generates more App Store revenue than markets three times its size. iOS holds roughly 30% market share, but Korean iOS users are among the highest-spending mobile users globally, with particularly strong engagement in gaming, entertainment, and lifestyle apps.
Korean localization requires care with formality levels (similar to Japanese) and Hangul-specific typography considerations. Korean users are early tech adopters and extremely discerning about app quality — including localization quality. Half-hearted localization performs worse than no localization at all in this market.
Expected download increase: 120-200% in the Korean App Store after quality localization.
Tier 2: High-Value Languages
These markets offer strong returns but may vary more by app category. Prioritize based on your specific audience.
Spanish (es)
Spanish is the world's fourth most-spoken language, covering Spain, Mexico, Argentina, Colombia, and 15+ other countries. The combined iOS user base across Spanish-speaking markets is enormous. However, ARPU tends to be lower than Tier 1 markets, and you need to decide between European Spanish (es-ES) and Latin American Spanish (es-MX or es-419). Apple supports both, and the differences in vocabulary, slang, and formality are significant enough that using European Spanish for a Mexican audience (or vice versa) feels jarring.
For most apps, Latin American Spanish reaches the larger audience. Spain has higher per-user spending. The ideal approach is to localize for both.
Brazilian Portuguese (pt-BR)
Brazil is the largest market in Latin America, with over 220 million people and a rapidly growing iOS user base. Brazilian Portuguese is distinct from European Portuguese — different enough that they're separate Apple localizations. Brazil's app economy is expanding fast, particularly in fintech, delivery, and social categories. The opportunity here is partly about current revenue and partly about market trajectory.
Pricing strategy is critical in Brazil. Purchasing power parity matters enormously — pricing at US levels will price you out of the market. Apps that combine proper pt-BR localization with locally appropriate pricing see dramatic adoption increases.
Italian (it)
Italy has a strong iOS presence in Western Europe, with higher iOS market share than Germany in certain demographics. Italian users respond well to localized apps, particularly in food, travel, lifestyle, and productivity categories. The market is mature enough to generate meaningful revenue but under-served enough by localized foreign apps to offer opportunity.
Dutch (nl)
The Netherlands has one of the highest iOS ARPU figures in Europe, driven by high disposable income and strong digital payment adoption. With only 25 million speakers (including Belgium's Flemish population), it's a small market — but an unusually profitable one per user. Dutch localization is also relatively inexpensive and straightforward from English.
Traditional Chinese (zh-Hant)
Traditional Chinese serves Taiwan, Hong Kong, and Macau — markets with high iOS penetration and strong spending power. Taiwan in particular has a disproportionately high ARPU for its population size. If you're already localizing into Simplified Chinese, adding Traditional Chinese is an efficient incremental step, though the localization goes beyond character conversion (vocabulary and cultural references differ).
Tier 3: Emerging Opportunity
These markets represent growth bets. Current App Store revenue may be modest, but trajectories are strong and early movers gain a lasting advantage.
Turkish (tr)
Turkey has a young, tech-savvy population and growing iOS adoption. The App Store market is expanding rapidly, and relatively few foreign apps have localized into Turkish, creating an opportunity for early movers. Pricing must be heavily adjusted — Turkey's currency volatility means purchasing power changes significantly over short periods.
Hindi (hi)
India's iOS market is small relative to its population (Android dominates with 95%+ share), but the iPhone-owning demographic is affluent and growing. As Apple invests in iPhone manufacturing in India and lower-cost models expand the user base, Hindi localization becomes increasingly valuable. The emerging markets opportunity for iOS apps is growing year over year.
Arabic (ar)
Arabic covers high-income markets (Saudi Arabia, UAE, Qatar) alongside large-population markets (Egypt). The Gulf states have strong iOS adoption and high spending. Arabic requires RTL layout support, which is a significant engineering consideration but increasingly well-supported by SwiftUI and UIKit. Saudi Arabia alone is one of the top 15 App Store markets by revenue.
Thai (th), Vietnamese (vi), Indonesian (id)
Southeast Asia is a fast-growing mobile market. While iOS share is lower than Android, the iOS segment is premium and growing. These markets are especially relevant for gaming, social, and lifestyle apps. Localization competition is minimal — very few Western apps have bothered with these languages, which means the first-mover advantage is substantial.
CJK Languages: Special Considerations
Chinese, Japanese, and Korean (collectively CJK) deserve special attention because they represent the highest-value localization targets but also the highest complexity.
Character Density and Length
CJK languages pack more meaning into fewer characters than alphabetic languages. Your 30-character App Store title limit actually gives you more information capacity in Japanese or Chinese than in English. This is an advantage — use it. You can fit more keywords and descriptive power into the same character budget. See our character limits guide for specifics.
Input Method Behavior
CJK users type using input methods (IME) that suggest words differently than alphabetic keyboards. This affects App Store search behavior. Japanese users might search using hiragana, katakana, kanji, or romaji — and the App Store indexes these differently. Your keyword strategy must account for input method behavior, not just direct translation.
Visual Expectations
Apps popular in CJK markets tend toward information density. Where a Western app might show three items per screen with generous whitespace, a Japanese or Chinese app might show eight with compact layouts. Your screenshots should reflect local aesthetic preferences, not just swap the text language on your US design.
Factors That Should Influence Your Priority Order
The tier ranking above is a general guide. Your specific priority should account for:
- App category — Finance apps over-index in Japan and Korea. Travel apps in European languages. Education apps in India and Brazil. Check category-specific revenue data on our statistics page.
- Existing organic traffic — If you're already seeing downloads from Germany without localization, that's a strong signal that localized listings will convert much better.
- Competition density — A market with ten localized competitors requires better localization than one with zero. But it also validates the opportunity.
- Your app's content type — Text-heavy apps (reading, productivity, business) benefit more from localization than visual apps (camera, photo editing) where the UI is largely universal.
- Regulatory fit — Some markets have specific requirements (China's ICP license, EU's GDPR, Brazil's LGPD). Factor compliance costs into your ROI calculation.
A Practical Localization Roadmap
Here's what a staged rollout looks like for a typical indie iOS app:
- Phase 1 (launch): Localize into Japanese, German, and French. These three languages cover the highest-revenue non-English markets with moderate localization complexity. This alone gives you coverage in the US (English), Japan, Germany, France, Canada (French), Belgium, Switzerland, and Austria.
- Phase 2 (month 2-3): Add Simplified Chinese, Korean, and Spanish (Latin American). This expands into the two remaining Tier 1 markets plus the largest Spanish-speaking audience.
- Phase 3 (month 4-6): Add Brazilian Portuguese, Italian, Traditional Chinese, and Dutch based on Phase 1-2 performance data.
- Phase 4 (ongoing): Expand into Tier 3 languages based on category fit and observed demand.
Scaling efficiently: AppStoreLocalization.com supports 45+ languages with AI-powered localization that handles keyword research, cultural adaptation, and metadata optimization. This makes it practical to move through all four phases in weeks rather than months — the per-language cost and turnaround time of AI localization removes the traditional barriers to broad market coverage. The automation guide explains how this works with App Store Connect.
What the Data Says About Revenue by Market
According to Sensor Tower's 2025 data, global App Store consumer spending exceeded $90 billion, distributed roughly as follows among the top markets:
| Market | Share of App Store Revenue | iOS Market Share | Localization Priority |
|---|---|---|---|
| United States | ~30% | ~57% | Already English |
| China | ~18% | ~24% | Tier 1 |
| Japan | ~14% | ~65% | Tier 1 |
| United Kingdom | ~5% | ~50% | Already English |
| Germany | ~4% | ~30% | Tier 1 |
| South Korea | ~4% | ~30% | Tier 1 |
| France | ~3% | ~28% | Tier 1 |
| Australia | ~2% | ~55% | Already English |
| Canada | ~2% | ~55% | French (fr-CA) |
| Taiwan | ~2% | ~45% | Tier 2 |
The pattern is clear: after the US and UK (which you're already serving in English), the next $35+ billion in App Store revenue requires non-English localization to access effectively.
Choosing which languages to localize into isn't just a linguistic decision — it's a business allocation decision. Start where the data points, measure results rigorously, and expand systematically. The revenue impact of localization is well-documented and, for most apps, the ROI timeline is measured in weeks, not quarters.
Frequently Asked Questions
What are the top 5 languages for iOS app localization?
Based on App Store revenue and market size, the top 5 are: Japanese, Simplified Chinese, German, French, and Korean. These consistently deliver the highest ROI for localization investment regardless of app category.
How many languages should I localize my app into?
Start with 3-5 Tier 1 languages (Japanese, Chinese, German, French, Korean) where the ROI is proven. Expand to 8-12 including Tier 2 markets once you see positive results. Going beyond 15-20 makes sense only for established apps with global ambitions.
Is it worth localizing into Chinese for the App Store?
Yes, China is the largest App Store market by downloads and second-largest by revenue. However, it requires Simplified Chinese specifically, and apps in certain categories need ICP licensing. Despite regulatory complexity, the revenue opportunity is enormous for apps that can operate there.
Should I localize into European Portuguese or Brazilian Portuguese?
Prioritize Brazilian Portuguese (pt-BR). Brazil has a much larger iOS market than Portugal, and the two variants differ significantly in vocabulary, spelling, and cultural references. Apple treats them as separate localizations.
What languages have the highest ROI for app localization?
Japanese consistently delivers the highest per-user revenue among non-English markets, followed by Korean and German. These markets combine high willingness to pay, strong iOS market share, and relatively low competition from localized foreign apps.
Sources
- Sensor Tower — "State of Mobile 2025" — sensortower.com/blog/state-of-mobile-2025
- StatCounter GlobalStats — "Mobile Operating System Market Share" — gs.statcounter.com/os-market-share
- Apple Developer — "App Store Localization" — developer.apple.com/app-store/product-page