App Localization: Definition, Tools, and Best Practices
The field of mobile app development has risen at a dramatically fast clip over the past several years and shows no signs
of slowing down. As of 2019, there are 2.46 million apps available for Android users, while Apple is close behind with
1.96 million in the App Store.
Much of this surge is thanks to international growth, but there remains a great deal of space left in the market. In large
countries with emerging economies such as Russia, South Africa, and Brazil, smartphone adoption is just 60 percent.
In order to appeal to these consumers, your app must cater to the needs and desires of smartphone users around the
world. This includes those who speak languages other than English. App localization is a critical concern for any mobile
app developer who wants to expand into non-English markets.
While English has truly achieved the status of a “global language,” not all users can speak English or want to speak it
when using a mobile app. 65 percent of multinational firms say that localization is important to achieving higher
company revenues. This figure is hardly a surprise when you consider that 75 percent of users prefer to buy products
in their native language.
In this article, we’ll discuss everything you need to know about app localization: what it is, the best app localization
tools, and best practices for app localization.
What is App Localization?
Mobile app localization is the process of developing a mobile app to adapt to languages and cultures other than the
Often, developers should consider not only languages but also dialects during localization. For example, Apple’s Siri
virtual assistant can speak in a variety of accents and dialects. This includes American, British, Australian, and South
African for English; Quebecois and France for French; and so on.
Regardless of the app’s purpose, size, or user base, localization is a best practice for mobile developers who want their
app to gain wide adoption. According to one study, translating the text of iPhone apps increased downloads by 128
percent. Having a localized user interface and text is an essential part of a seamless and high-quality mobile app
Localization is often conflated with the similar process of internationalization. Internationalization means designing a product for easy adaptation and use in multiple international markets. You can think of internationalization as the foundation that underpins and enables localization.
In the next section, we’ll go into more detail by discussing four parts of your mobile app that need localization.
4 Parts of Your Mobile App That Need Localization
Text is the most obvious part of the mobile app that requires localization, but far from the only consideration. Below
are four factors to consider when localizing your mobile app.
Text is the first place to start with mobile app localization, and will likely yield the greatest return on your investment.
You should localize (i.e. translate) all parts of the app’s text. This includes the user interface, other text strings, in-app purchases, the app’s name and description in the app store, and any ad campaigns.
Also, consider localizing the app to fit multiple dialects of the same language. For example, British people speak of “dustbins” and “chemists." However, their American counterparts speak of “trash cans” and “drugstores.” Dialect localization is important if two dialects are very different, or if users strongly prefer to read their own dialect.
Finally, not all writing systems use the same layout. Hebrew and Arabic use a script from right to left, for example,
while some Asian languages use a vertical script. Translating your app into these languages may thus also require
changes to the app’s user interface.
Images, videos, and symbols are a less obvious but important target for localization. Users from different regions or
cultures may not understand your app’s multimedia content, or may even perceive it as offensive. If multimedia content
has text captions or descriptions, these also need localization.
For example, your mobile app might use a red “stop” sign to indicate that the user should stop a particular activity.
However, the shapes and text content of stop signs differ around the world. Japan, for one, uses an inverted red triangle
with the Japanese word for “stop”. As a result, the familiar octagonal shape of Western stop signs may not be familiar to
3. Dates and times
Different countries and cultures will have different ways to count time. The “little-endian” format (e.g. “1 January
2000”) is the most popular way to write dates worldwide. The U.S. takes a different approach by inverting the day and
month (e.g. “January 1, 2000”).
The U.S. is also an outlier using the 12-hour clock, in which the time passes from 12 to 1 at noon and midnight. Most
countries make use of the 24-hour clock (also known as “military time”). However, note that there are slight variations
in its use between countries and languages.
If your mobile app deals with questions of money, currency localization is likely necessary. (This excludes things like in-
app purchases, which the phone itself should handle.)
Most obviously, your app should be able to convert between currencies if necessary. For complete accuracy, you also
need to consider factors such as currency symbols and their positions.
The dollar sign $, for example, represents not only the U.S. dollar but also a version of the peso in many Latin American
countries. Other important symbols include the British pound (£), the euro (€), the Japanese yen and Chinese yuan (¥),
and the Indian rupee (₹). Whereas the dollar sign comes before the amount in the U.S., the opposite is true for
currencies such as the euro.
App Localization Tools and Techniques
There are a variety of ways to perform mobile app localization, depending on your needs and budget. Large app
development teams will often hire a "localization engineer." This person is responsible for overseeing the app's localization process.
Some companies offer an entire suite of app localization services, including human translators. Companies such as OneSky, Lokalise, and POEditor handle every aspect of the process from start to finish. These solutions are full-blown
translation management systems that include automation and optimization.
In addition, localization experts often use tools to speed up the process of localization:
• Translation memories are database tools that store previous translations of titles, sentences, and paragraphs.
This helps improve productivity and translation quality.
• Termbases are glossaries that contain industry-specific terms and expressions and their translations into other
languages. Maintaining these verified translations improves the consistency of the final translation.
3 App Localization Best Practices
1. Research your users
In large part, app localization is a matter of getting the most bang for your buck. There’s no sense in adapting your
mobile app to work with the Julian calendar, for example, when it’s scarcely been in use since ancient Rome.
As such, it’s important to research your audience (or potential audience). You need to understand who they are and
what their expectations might be in terms of localization.
To get started with localization, select two or three target markets outside your own with the greatest return on
investment. When localizing an app for tea drinkers, it makes sense to focus on large markets like the United Kingdom,
China, and Turkey where the population drinks the most tea.
2. Research your competitors
Researching your competitors’ efforts at localization can help you understand how to get started. Download their apps
and play around with the settings to see how they handle users in different languages and regions. You can also use
tools like MightySignal to scan these apps and see which SDKs they have installed and uninstalled, including any SDKs
that offer localization services.
Want to see how some of the top mobile apps have handled the question of localization? There are many app
localization case studies available online. Developers for apps such as Paper and Defender’s Quest have written
accounts of their experiences with app localization.
3. Get user feedback
Already implemented localization for your mobile app? Understand how users react to it via both explicit and implicit
feedback. Scan reviews of your app in the app store to see if users are complaining about localization issues. You can
also use pop-up dialogues in the app to ask users whether they are happy with the localization.
Mobile app analytics tools also provide insights into whether users in different regions have problems with your app’s
localization. For example, you might find that users from one country are much more likely to quit the app during the
onboarding process. This could be a sign that the localization for that country or language is of poor quality.
Smartphone adoption continues to grow worldwide, which makes mobile app localization even more important for developers. Apple's App Store now supports 155 countries and regions and over 40 different languages. This is just one sign that mobile app development is a truly global phenomenon.
To understand the best practices and top trends in app localization, you need to know where other app developers stand. MightySignal breaks down any iOS or Android mobile app to deliver data-driven insights, revealing the SDKs that it uses as part of this functionality. You can use MightySignal to find top app localization SDKs such as OneSky and localize and determine the best option for your own app localization needs.
Ready to start making smarter decisions for your mobile app? Contact the MightySignal team to schedule a demo of our mobile app intelligence platform.