Nine Things to Think About When Localizing Your Mobile App
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Nine Things to Think About When Localizing Your Mobile App

Nine Things to Think About When Localizing Your Mobile App

9 Things to Think About When Localizing Your Mobile App

The numbers are staggering:

  • Between Apple iOS and Android, there are 4 million apps for smartphones and tablets
  • The number of mobile phone subscribers globally is near 5 billion
  • 90% of activity on mobile devices occurs in apps

That’s an enormous worldwide potential market for your app. But it will stand out from the crowd only if you have a very local, flawlessly usable product. Consumers will expect an experience that looks, feels, sounds, and performs as if it were produced by software developers from their home town.

This is the outcome of carefully planned and executed localization. Here we share the nine things you need to know about localizing your app. 

1. Internationalize

Localization does not start when you translate the first word. There are ways to prepare your app so it translates easily, quickly, and cost effectively. Enter internationalization. It’s the design and building of software to make sure the underlying source code is language-neutral. Internationalized code will handle varying date, currency, and number formats, locale and cultural considerations, and UI factors such as space limitations, encodings, and fonts. The result is localization-ready code: one set of source files that can be used across multiple languages, countries, and locales.

2. Externalize your resources

The assets, or resources, of your app are all the elements that aren’t related to the code. Resources include text, images, tutorials, or any other data file that accompanies your program’s executable code. For optimum mobile app localization, you’ll need to do two things:

  1. Extract UI strings from your code. Separating the textual content into an external file will allow you to adjust the content without changing any of the code itself.
  2. Make multiple resource filesone for each target languageand translate the text in each file. This way, when a user opens your app, the smartphone OS will load whichever language resource file matches the user’s language setting.

3. Design for localization

You want to make sure your app’s layout will accommodate other languages. Different languages take up different amounts of space. French, Spanish, and German, for example, can take up to 30% more space than English. Keep your design flexible to accommodate this; ensure that your app allows for the expansion and contraction of texts. The goal is to be able to use a single set of layouts for all the languages you support.

4. Consider culture

A culturally neutral design means you don’t have to adapt your app for each market. Is your app full of icons, images, and colors? Cultural references? Be aware that these things aren’t universal; what can be acceptable in one culture might offend in another. A baseball icon might not appeal in a country where cricket reigns. An image of a dog might offend or confuse some in a Middle Eastern culture. Green is the traditional color of Islam but in China it’s a sign of adultery. Do your research and use design elements for a global audience.

5. Test before loc

Testing before localization will uncover international functionality issues, ensure all the code in the product is “global-ready”, and check that string resource externalization has been successfully completed. This testing—part of the internationalization process—verifies whether the product was correctly adapted to work in different languages. It’s how you’ll uncover and fix issues caused by unforeseen bugs that would increase the costs of both localization and future product support.

6. Use the right translators

Because of the rise in apps, many translators are beginning to specialize in app localization. They will understand the constraints and requirements of localizing for a small screen. Some may have copywriting skills, which will help if they need to fit the translation within the text length limits while maintaining the original meaning. Even better if you can find translators who are a fan of your product or who use your app.

7. Prepare your translators

It’s important to provide them with the right reference materials: glossaries with key product terms, translation memories so past-approved translations can be reused, and style guides that will show a translator how to maintain your brand’s voice and vibe in their language.

Also, give your translators context when you send them your resource files. Providing the working app is ideal; screenshots would also suffice. If your translators know where the words they are translating are meant to go, they’ll work more accurately and be more productive.

8. Test after loc

Once your resources are translated, it’s time to move everything back into your app for more testing. At this stage, you’ll conduct rigorous localization testing and linguistic testing to make sure there are no issues in your content or layout.

First, you need a testing environment that includes multiple virtual devices and different screen sizes. These will vary depending on the markets you decide to target—do your research so you don’t waste valuable testing time.

Your testers, bilinguals with testing experience, will go through your app in detail. Give them a test plan so they know exactly what they need to look at. They will be able to find things such as UI display issues, line wrapping, breaks in sentences and strings, incorrect layout, and any text that hasn’t been translated. They also will likely catch any translation errors. They’ll provide these bugs in a report so you can fix them before you go live.

Ideally, you would have your testers work on the actual device, but you can also test through screen shots, emulators, or a staging server.

9. App Store Optimization (ASO)

And lastly, make sure the world knows your app exists. App Store Optimization (ASO) is about priming your content to get greater visibility in the app store. It’s a cousin of SEO: you’ll need to make sure that you’re using the right search terms and optimized content for each locale. Also, correct translations of your app’s name, description, and keywords will help local users find it more easily.


Mobile app localization is way more than just translating the interface. By taking the time to properly plan and execute internationalization, testing, and ASO, as well as work with qualified linguists with app localization experience, your app should be ready to make a worldwide splash.