Xlocalize
Localize xcstrings
Our Mac app that translates String Catalogs
App localization
iOS app localization: speak your users’ language
Develak localizes iOS apps end to end: String Catalogs, translated interfaces, localized App Store listings and screenshots, and testing in every language. Our own apps ship in up to 44 languages, and we built Xlocalize, a Mac app that translates .xcstrings files.
- String Catalogs
- .xcstrings
- Plurals
- Right-to-left
- Localized ASO
The service
What is iOS app localization?
Localization adapts an app to another language and region. It covers every string of the interface, but also plurals, dates, numbers, currencies and units, layouts that must stretch for longer words, and right-to-left scripts such as Arabic and Hebrew. Done well, users forget the app was ever written in another language.
The modern way to localize an iOS app is the String Catalog: a single .xcstrings file, introduced with Xcode 15, that holds every string, its translations and its plural variants. We set it up properly — extraction, comments for translators, variants — so each new release stays in sync across languages.
Localization also multiplies your reach on the App Store, where each locale has its own metadata and its own search results — see our App Store Optimization service. Our full method is explained in the guide How to localize an iOS app with String Catalogs.
At a glance
- Service
- Localization of iOS apps and App Store listings
- Format
- String Catalogs (.xcstrings)
- Scope
- Interface, metadata, screenshots, testing
- Our practice
- Our own apps ship in up to 44 languages
- Tooling
- Xcode and Xlocalize, our own Mac app
- Works best with
- App Store Optimization
What’s included
What our localization service includes
Everything that has to change when your app changes language.
String Catalog setup
We migrate or configure .xcstrings, extract every string and add context comments so translations are accurate.
Translation & adaptation
Interface text translated and adapted for each market, with terminology kept consistent across the app.
Plurals, dates & formats
Plural rules and number, date, currency and unit formats handled by the system, never by hand.
Layout & right‑to‑left checks
Screens tested for long words, large Dynamic Type sizes and right-to-left languages.
Localized App Store listing
App name, subtitle, keywords, description and screenshot captions for each locale.
Linguistic QA on device
Every language reviewed in the running app, on a real device, before release.
String Catalog
One file, every language
All the text of your app lives in a String Catalog: every key, every language and every plural form, kept in sync by Xcode at each build.
Plurals done right
English has two plural forms, Arabic six and Japanese one. The catalog stores each variant, so counts always read naturally.
Right‑to‑left included
Arabic and Hebrew mirror the whole interface. SwiftUI handles most of it; we check the rest on device.
Nothing left behind
Xcode flags new and changed strings, so a translation cannot silently go missing from an update.
Who it’s for
Who should localize their app?
If people outside your home market could use your app, localization is often the most effective update you can ship.
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Apps with international potential
Utilities, health, sports and hobby apps travel well: the need is universal, only the language changes.
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Apps plateauing in one market
New countries mean new search results and new users, without changing the product itself.
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Developers drowning in strings
Your app grew and the strings got messy. We move you to String Catalogs and a clean workflow.
Deliverables
What you receive
A localized app, localized listings, and a workflow that keeps them in sync.
- A clean String Catalog (.xcstrings) for the whole app
- The interface translated into every target language
- Localized App Store metadata for each locale
- Localized screenshot captions
- Checked layouts, plurals and formats
- Right-to-left review where relevant
- A glossary of your product terms
- A workflow to translate future updates
Process
How we localize your app
Groundwork once, then every language follows the same path.
Audit
We check how strings are defined, find hard-coded text and flag layouts that won’t survive longer languages.
You get: Localization audit
Prepare
String Catalog set up, strings extracted, context comments written and plural variants defined.
You get: String Catalog
Translate
Interface and store metadata translated, then adapted to each market’s conventions and search terms.
You get: Translated UI & listing
Test
Every language checked in the running app: truncation, plurals, formats and right-to-left layouts.
You get: QA in every language
Release & maintain
Localized build and listings shipped together, with a process that keeps new strings translated.
You get: Localized release
Timeline
How long does app localization take?
The first languages take the longest, because the groundwork happens once. As a guide:
Audit & String Catalog
Typical duration: A few days
Strings extracted and commented.
Translation
Typical duration: Days to a few weeks
Interface and store metadata.
QA on device
Typical duration: A few days
Every language, every screen.
Release
Typical duration: With your next update
App and listings together.
Guidance, not a guarantee: the number of languages and strings sets the real schedule.
Tools & frameworks
The localization toolkit
Apple’s native localization stack, plus a tool we built because we needed it ourselves.
- String Catalogs
- One .xcstrings file for every language.
- Xcode
- Extraction, previews and pseudo-languages.
- Xlocalize
- Our Mac app that translates .xcstrings files.
- Foundation formatters
- Dates, numbers and currencies per locale.
- Plural variants
- The grammatical rules of each language.
- SwiftUI previews
- Every screen checked in every language.
- App Store Connect
- Localized metadata and screenshots.
- Right-to-left layouts
- Mirrored interfaces for Arabic and Hebrew.
Proof
Localization is how we ship every app
Every Develak app is localized, most of them into dozens of languages — and we built our own translation tool for String Catalogs along the way.
FAQ
App localization: your questions
What developers and publishers ask us about localizing an iOS app.
Ask your question Not covered here? Write to us — we answer every message ourselves.
contact@develak.comWhat is the difference between translation and localization?
Translation converts text into another language. Localization adapts the whole experience: plurals, dates, currencies and units, layouts for longer words, right-to-left scripts, and the App Store listing and screenshots of each market.
What are String Catalogs (.xcstrings)?
String Catalogs are Apple’s localization format, introduced with Xcode 15. A single .xcstrings file stores every string of an app, its translations, its plural variants and comments for translators, replacing the older .strings and .stringsdict files.
How many languages should my app support?
Start with the markets where your category is popular and competitors are weak — usually a handful of major languages — then expand based on data. Develak’s own apps ship in up to 44 languages, but more is not always better for a first step.
Do you use machine translation?
Our workflow combines AI-assisted translation with human review. Xlocalize, our Mac app, translates String Catalogs with models such as Claude, GPT or Gemini, using translator comments as context; every language is then reviewed in the running app. For sensitive wording such as medical or legal text, we recommend a review by a native speaker and can work with your own translators.
Do you also localize the App Store listing?
Yes. Name, subtitle, keywords, description, promotional text and screenshot captions are localized for each locale. It is often the part with the highest return, because it opens up search results in every country.
Can you localize an app we built ourselves?
Yes. We audit your project, move it to String Catalogs if needed, then handle translation and testing. Your team keeps a clean workflow for future releases.
Do you support right-to-left languages like Arabic?
Yes. SwiftUI mirrors layouts automatically for right-to-left languages such as Arabic and Hebrew; we then check every screen for icons, alignment and custom views that need attention.
Take your app worldwide
Tell us which markets you have in mind. We’ll suggest where to start.