How to Localize App Store Keywords for Better ASO

The App Store keyword field is 100 characters of pure leverage. It is the single most important factor for search discoverability — and it is the field that developers butcher most often when localizing. The mistake is almost always the same: they take their English keywords, run them through a translator, paste the output, and wonder why they get zero impressions in Japan.

Direct keyword translation does not work. Not sometimes — almost never. This guide explains why, and walks through the right way to localize App Store keywords for each target market.

How the App Store Keyword Field Works

Before diving into localization strategy, let's make sure the fundamentals are solid. The App Store keyword field has specific mechanics that differ from Google Play and from web SEO:

• 100 characters per locale. This is a hard limit. You get exactly 100 characters to work with in each localized version of your metadata.
• Comma-separated. Individual keywords or short phrases are separated by commas. Do not use spaces after commas — they waste characters.
• Not visible to users. Unlike your app name and subtitle, keywords are hidden. Users never see them. This means you can use competitor names, alternate spellings, and terms you might not want publicly associated with your brand.
• No need to repeat. Words that already appear in your app name or subtitle are automatically indexed. Do not waste keyword characters repeating them.
• Singular forms only. Apple's algorithm matches both singular and plural from a singular keyword. "photo" matches searches for both "photo" and "photos." So use the singular form to save characters.
• Apple indexes combinations. If your keywords contain "budget" and "tracker," Apple can match the search query "budget tracker" even though that exact phrase is not in your keyword field. This means individual words are more space-efficient than phrases.

For the full breakdown of character limits across all metadata fields, see our App Store character limits reference.

Why Direct Translation Fails

Here is a concrete example. Say you have a habit-tracking app and your English keywords include:

You might translate these to Japanese and get:

The problem? Several of these terms are unnatural in Japanese:

• "トラッカー" (torakkā / tracker): Japanese users rarely search for this English loanword. They search for "管理" (kanri, meaning management) or "記録" (kiroku, meaning record/log).
• "ストリーク" (sutorīku / streak): This English loanword has almost zero search volume in the Japanese App Store. Japanese users would search for "連続" (renzoku, meaning consecutive/continuous).
• "ウェルネス" (uenesu / wellness): While used in some Japanese marketing contexts, actual App Store search volume for this term is negligible compared to "健康" (kenkō, meaning health).
• "自己改善" (jiko kaizen / self-improvement): Grammatically correct but not how Japanese users search. They might search for "自分磨き" (jibun migaki, meaning self-polish/betterment), a more colloquial term.

A properly researched Japanese keyword set would look entirely different:

Notice: "朝活" (asa-katsu, meaning morning activity — a popular Japanese lifestyle concept), "三日坊主" (mikka bōzu, literally "three-day monk" — the Japanese idiom for someone who cannot stick with habits), and "日課" (nikka, meaning daily routine). These are terms a translator would never produce but that Japanese users actually search for.

The Keyword Localization Process

Step 1: Identify Your Core Concepts

Start by listing the concepts your app relates to — not the specific English words, but the underlying ideas. For a budget app, these might be: money management, expense tracking, budgeting, saving, financial planning, bills, income. These concepts are universal; the words used to search for them are not.

Step 2: Research Local Search Terms

For each target locale, you need to find what users actually type when searching for these concepts. Several approaches work:

• App Store search suggest: Change your device's region and language, then type partial terms in the App Store search bar. The autocomplete suggestions reflect real search behavior in that locale.
• Competitor analysis: Look at top-ranking apps in your category in each target locale. What keywords do they use in their titles and subtitles? Since those are visible, they reveal what terms are valued in that market.
• ASO tools with locale data: Tools like Sensor Tower, AppTweak, and App Annie provide search volume estimates per locale. These are not perfect, but they indicate relative keyword popularity.
• Native speaker review: Have someone who actually lives in the target market review your keyword candidates. What sounds natural? What would they search for?

Step 3: Understand Local Search Behavior Patterns

Different markets have fundamentally different search behaviors:

Advanced Keyword Strategies by Locale

Leveraging Cross-Locale Indexing

Apple has a little-known feature: certain locale pairs share keyword indexing. The most important one is that keywords set for English (US) are also indexed in English (UK), English (Australia), and English (Canada). Similarly, Spanish (Mexico) keywords index in Spanish (Spain) and vice versa — though you can also set separate keywords for each.

More interestingly, some non-English locales also index English (US) keywords. This means your English keywords may already provide some (limited) coverage in markets like Japan, Germany, and France. However, this is no substitute for native-language keywords — it just means English terms with universal recognition ("VPN," "PDF," "WiFi") do not need to be repeated in every locale's keyword field.

CJK Character Efficiency

In Chinese, Japanese, and Korean, you can fit significantly more keyword concepts into 100 characters than in English or other Latin-script languages. A single Chinese concept like "记账" (bookkeeping/accounting) is two characters, while the English equivalent "bookkeeping" is eleven. This means your CJK keyword fields can be far more comprehensive.

In Japanese, do not use commas between individual kanji words — Apple's tokenizer handles this automatically. Use commas only to separate distinct concepts that should not be merged. This saves characters and lets the algorithm create more combinations.

Handling Synonyms and Variants

Every language has multiple ways to express the same concept. In your English keyword field, you might choose between "photo" and "picture" and "image." The same multiplicity exists — usually more so — in other languages. German has "Foto," "Bild," and "Aufnahme." Japanese has "写真" (shashin), "フォト" (foto), and "画像" (gazō).

You cannot include every variant. Prioritize by search volume. Use App Store search suggest as a free proxy: terms that appear higher in autocomplete generally have higher search volume. If you are using ASO tools, check volume estimates for each variant and pick the ones with the highest traffic.

Character Limit Strategies

The 100-character limit forces ruthless prioritization. Here are strategies to maximize the value per character:

1. Never repeat words from your title/subtitle. They are already indexed. Every repeated word is wasted space. If your localized title includes "写真" (photo), do not put it in keywords too.
2. Use singular forms. Apple matches plural automatically in most languages. "foto" matches "fotos" in Spanish.
3. Drop articles and prepositions. "de," "la," "das," "の" — these add characters but add no search value. Users search for "photo editor" not "the photo editor."
4. Use individual words, not phrases. Since Apple combines keywords, "budget,tracker" is better than "budget tracker" because the former also matches "budget" and "tracker" individually.
5. No spaces after commas. Every space is a wasted character. Write "photo,edit,filter" not "photo, edit, filter."

For the complete reference on what fits where, see our character limits guide.

Measuring Keyword Performance by Locale

After deploying localized keywords, you need to measure whether they are working. App Store Connect provides per-territory data on:

• Impressions: How many times your app appeared in search results. A jump in impressions after a keyword change indicates your new keywords are matching real searches.
• Product Page Views: How many users tapped through from search results. A healthy ratio of page views to impressions (typically 5-15%) means your title/icon are compelling in that locale.
• Conversion Rate: The percentage of product page viewers who downloaded. If localized keywords bring traffic but conversion is low, your description or screenshots may need localization too — see our description best practices.

Give each keyword change at least 2-3 weeks to accumulate meaningful data before evaluating. App Store indexing is not instant — it can take several days for new keywords to be fully indexed and start generating impressions.

Common Keyword Localization Mistakes

1. Using Google Translate for keywords. Machine translation produces grammatically plausible but search-irrelevant output. A translated keyword that no one searches for is worth exactly zero.
2. Assuming one Spanish covers all Spanish markets. Mexican users search differently from Spanish users. "Celular" (Mexican) vs. "Móvil" (Spanish) for mobile phone. "Computadora" vs. "Ordenador." If your app is relevant in multiple Spanish-speaking markets, consider which Spanish locale drives more revenue and optimize for its vocabulary. Read more in our localization vs. translation guide.
3. Ignoring English loanwords in non-English markets. Japanese users search for "アプリ" (apuri, from "app") not "応用" (the formal Japanese word for application). Korean users search for "다이어트" (daieoteu, from "diet") alongside "식이요법" (the native Korean term). Loanwords are often the higher-volume term.
4. Not using all 100 characters. Leaving characters unused is leaving discoverability on the table. If you have 15 characters left, find another relevant term to add.
5. Copying competitor keywords blindly. A competitor's keywords might be poorly chosen too. Use competitor analysis as one input, but validate against search volume data and autocomplete suggestions.

Scaling Keyword Localization

Doing this properly for even five locales is a significant research project. For 15-20 locales, it is a full-time job. And it needs to be revisited regularly as search trends shift.

This is one of the core problems that AppStoreLocalization.com solves. Rather than translating keywords, the service performs locale-specific keyword research using AI trained on App Store search patterns, generating keyword sets that reflect actual local search behavior across 45+ languages. The output respects character limits, avoids duplication with your title/subtitle, and prioritizes high-volume terms — the same process described in this article, but automated and applied at scale.

Whether you do it manually or use tooling, the principle is the same: keyword localization is research, not translation. Treat each locale's keyword field as its own ASO project, and you will outperform the vast majority of competitors who are still pasting Google Translate output into their keyword fields.

For a broader view of the full localization process beyond keywords, see our complete App Store localization guide.