App Localization

Smartling App Localization Services

Mobile app stores have officially gone global, and the next person to download your app could be located anywhere. But while your app may be globally available, it may not be global-ready. Today, localizing apps for key audience segments is a must. This is true for both iOS app localization and Android app localization.

Why App Localization Matters

Localizing apps for your target audience is good business practice, but it’s also a process that demands a clear business case before companies can invest the required resources.

For any colleagues that still need convincing, here are just a few of the reasons why app localization deserves a place in mobility plans:

  • 90% of mobile device activity now occurs within apps, as opposed to browsers.
  • Worldwide mobile app revenues will rise from $51 billion in 2016 to $101 billion in 2020.
  • At that time, consumers across the APAC and EMEA regions will combine to generate 3.8x as many mobile app downloads as their counterparts in the Americas.

What Is The ROI of App Localization?

  • A study, “The Impact of App Translations” from Distomo showed that localizing iPhone application text resulted in significantly more downloads – 128% more per country, in fact.
  • Not only that, but companies saw a 26% increase in revenue for each country added via app localization. What’s more, these results were achieved within just one week of offering a localized app.
  • The “app localization effect” on app downloads is striking. App developer David Janner ran an experiment with app translation. He found that 76% of the total app traffic came from English-speaking countries prior to app localization. And after? English-speaking users made up only 10% of the total, while the total volume leaped from 3,000 downloads per month prior to app localization to 23,000 downloads per month post-localization – or 767% more downloads.

Localization vs. Internationalization

App Localization Benefits

What’s the difference between localization and internationalization?

Internationalization (abbreviated “i18n”) prepares your app to make it easier for localization to take place later on. Internationalization generally requires you to change your software to ensure that it isn’t geared toward a single country, locale, language, or culture.

Localization services (l10n) is different. It requires you to add appropriate resources to your software to ensure that a given country, locale, language, or culture is supported.

Think of it this way – internationalization produces global-ready software that can easily be localized for a given market. App localization, which is a subset of software localization, is traditionally the second step in the process. It enables you to actually adapt software for another market.

In the past, app localization generally took place after internationalization. However, modern translation software can significantly reduce or eliminate the need for you to internationalize your application.

Localizing iOS and Android Apps

You want to get your app in front of the largest possible group of people. And of course, you want to hit the major platforms, especially iOS and Android. There are a number of best practices for cross-platform app localization.

Whether you’re localizing iOS or Android apps, here are some best practices to follow for app localization:

1. Resources

Think of resources as everything in your app that is not code: content, images, videos, etc. Resources are data files that accompany a program’s executable code. Resources simplify the code you have to write by moving the creation of complex sets of data or graphical content outside of your code and into more appropriate tools. To take advantage of a resource, all your code has to do is load it at runtime.

Externalize resources

The first step in the app localization process is to place your resources into external files. After that, localization becomes a simple process of creating new versions of the resource files for each supported language.

Default resources

Ensure that your app runs properly, regardless of language or locale, by maintaining a set of default resources. The app’s default resources are those that are not marked with any language or locale qualifiers.

2. Layout

When designing an app you plan to localize, you’ll need to consider the length of words and sentences in languages other than English. You’ll also want to consider spacing, left-to-right and right-to-left support, as well as other factors.

Flexible layout

As you design your layout, you want to ensure that it can accommodate both expansion and contraction of text. For example, content translated in German can take up to 30% more space than English, while Finnish expands up to 60%. You also want to consider vertical variations for languages whose characters contain smaller or larger than the Latin alphabet.

Keep those considerations in mind as you design your app, and you should be able to use a single set of layouts for all the languages you support. For languages that still won’t fit your flexible layout, create alternative layouts that can then be loaded with the resource files for those specific languages.

Right-to-left (RTL) layouts and text

If you plan on doing app localization in Hebrew, Arabic, or Persian, where right-to-left (RTL) scripts are used, consider implementing support for RTL layouts and text display to the extent possible.

System-provided formatting methods for dates, times, numbers, and currencies

When your app displays dates, times, numbers, currencies, and other entities that can vary by locale, use the system-provided formats rather than creating your own app-specific formats. Not every locale uses the same thousands separator, decimal separator, or percent sign.

3. Context

Making context available to your app translation team can make a noticeable difference in terms of translation quality. Translators can choose wording based on the content’s location in the app but also the space available. This is true no matter what form of content you translate, but is especially relevant for mobile app translation, where the size of the screen is constrained and can vary from one device to another. Giving translators context can significantly speed up app translation.

When translators work in Smartling on an app translation project, they are able to see their translation in context. For phone apps, context is made up of screenshots of the apps’ different interfaces that are uploaded to the dashboard. Start building your screenshot library now so that when the time comes to translate the app, you’ll be set to upload the content.

4. Testing

Once you receive your translated strings and resources and move them back into your apps, test the app to ensure that there are no localization issues in your layout and content.

Test environment

To test your localized app, set up an environment that includes multiple devices (or virtual devices) and screen sizes and is based on the markets and form factors you’re targeting. Note that the range of devices in specific regions might be different. If possible, match your test devices to the actual devices most likely to be available to users.

In addition to setting up testing environments, start testing using Smartling’s pseudo translations. You can download pseudo translations from the Files view in each of the target languages setup for your project. The file contains the original strings with added characters so that it can be used for QA and layout purposes.

Common localization issues

On each test device, set the language or locale in the Settings menu. Install and launch the app, and then navigate through all of the UI flows, dialogs, user interactions, and enter text in inputs. Some things to look for include:

  • Clipped text or text that overlaps the edge of UI elements on the screen
  • Poor line wrapping
  • Incorrect word breaks or punctuation
  • Incorrect alphabetical sorting
  • Incorrect layout direction or text direction
  • Untranslated text. If your strings display in the source language instead of translation, you may have overlooked those strings for translation or marked the resources directory with an incorrect language qualifier.

For cases where your strings’ translations have expanded and no longer fit your layouts, adjust your default layouts. If this doesn’t resolve the issue, create a custom layout for the language.

Test for default resources

After you’ve tested your app in all of your supported languages and locales, test it again in an unsupported language and locale to ensure it properly reverts to your default resource file. Also make sure your app includes a full set of default strings and resources so that it is usable to all users regardless of their preferred language.

5. App Store

The App store listing is the first impression international users have of your app, so highlight what’s great about it in all local versions. Don’t forget to localize:

  • App description
  • App screenshots on phones and tablets
  • Promotional graphics and videos

With these five areas, you’ve covered all of the major steps you need to localize your app for iOS and Android.

The Smart Way to Localize Your App


Using a translation management system makes it easy to integrate app localization directly into your development process so that you can focus on rapidly creating and delivering the best features and user experiences. Translation management technology makes it fast and easy for you to localize your app by automating many steps in the process and eliminating translation-related delays.

Many of the world’s leading mobile businesses use Smartling’s localization software to speed up and facilitate app localization, such as:

Localize your mobile apps for any language or platform, including Apple iOS (iPhone and iPad) and Android. The Smartling localization tool natively supports all of the standard file formats, including Apple iOS strings, Android XML, and XLIFF, so you can get started immediately.

  • Deliver the highest-quality localized experience with professional human translation using your translators or Smartling’s partner agencies
  • Smartling’s enterprise-grade API automatically collects your strings, submits them for translation, and returns the translated strings directly to you
  • Cost-saving translation memory ensures that you pay to translate each string only once, regardless of the number of apps and platforms in which it’s used
  • An in-context interface in the translation tool allows translators to see how each translation will appear in your apps and to account for the available space

Don’t miss out on the opportunity to deliver your app to the world. Get started with Smartling today.

App Localization