What is localization testing and why is it important?

Every application needs localization to maximize their return on investment in new markets. Functionize’s data-driven localization testing can help you do this effectively.

Every application needs localization to maximize their return on investment in new markets. Functionize’s data-driven localization testing can help you do this effectively.

December 16, 2021
Tamas Cser

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Every application needs localization to maximize their return on investment in new markets. Functionize’s data-driven localization testing can help you do this effectively.

What is localization testing?

To capture markets around the globe, businesses need to globalize their applications. This means delivering features, language and cultural nuances to make customers in your target markets want to use your application. Globalization includes both internationalization and localization.


Globalization = Internationalization + Localization

To get your application ready for globalization, it will require a certain degree of complexity. You need to consider many variables such as different languages, formats, legal & compliance needs, APIs, operating systems and devices. Any of these touchpoints can throw a localization error. That also means there are many opportunities to incorporate data-driven testing to reduce your risk. 

Internationalization entails developing language-neutral architecture and functionality. It makes the application “world-ready”. This means you need to be ready to drill down to locale-specific versions. This part of testing is more design testing, rather than functional testing. 

Localization entails developing that locale-specific version. You need to make the necessary content and UI changes. Localization needs to be tested thoroughly before going live. You do not want a cultural faux pas to break the customer journey for an entire market. This is where data-driven localization testing comes in.

Not just language

It’s easy to assume that accurate translation will cover all your localization needs — this is not the case. There are various application layers, components and touchpoints that make up localization. Analytics teams around the world are rife with stories of high bounce rates because users could not register with their own naming customs. 

Localization goes beyond language-specific aspects and covers functionality, display and cultural appropriateness. 

Let’s look at a few examples of what localization testing needs to cover.


Make sure that all your application content translates correctly to your target language. This means you should consult native speakers who can catch semantic errors. Conversely, you should avoid using a translation engine since it has limitations. For example, try using Google Translate to convert a phrase in English to another language. Then, translate the result back to English. You’ll see that online tools don’t quite capture everything. Translation needs to be a human-augmented effort.

Additionally, you’ll need to test all your UI elements for misplaced or truncated text. Buttons, headers, boxes, form fields – they all need to follow your original UI design. This is especially true for languages that read from right to left, such as Urdu, Hebrew and Arabic. Factor in language-specific punctuation, capitalization, line breaking, work breaking, text direction and justification – so many variables can cause design issues.

Twitter took their localization to another level by delivering a feminine language setting to the Middle East. Arabic is one of many languages that have masculine and feminine grammar.

Numerical Formats

If your application has numerical inputs, outputs or displays, you will need to test them. Keep in mind that numbers like the date, time, currency, phone numbers, area codes and measurement units all vary by country. 

Your customer should not struggle with payments or scheduling because of such syntax issues. Some countries do not have zip code systems, so users have to constantly input dummy data into this field with even the most popular applications today.

Support Components

Localization testing also checks supporting components. These components could be default spelling checkers, speech engines and hotkeys. Font families and how they connect to keyboards on different devices can affect the most basic level of user experience. Ignoring these language support features will restrict your products and services from reaching those markets. 

Don’t forget to test support materials such as help documentation, license agreements, and product documentation for a global audience.


When you need to connect many software modules and third-party APIs to your application, you will need to test all those components. Check for compliance with local regulations governing software distribution and installation. 

Even your hardware needs to be tested. Your new market’s users should have access to the necessary drivers and devices. Those connections should be seamless. Country-specific laws apply to the encryption algorithms your application uses.

Moreover, the location of the servers your application uses impacts the user experience. This is important in hybrid cloud and edge models used by many businesses today.

Table 1: Examples of variables covered in localization testing

Implementing localization testing

Localization testing needs significant human effort in the early stages. Make sure to thoroughly research and document your market’s cultural needs before providing guidance on localization testing. Data-driven localization using tools makes your work easier – but only if you have the data.

How Functionize makes localization testing easy

Functionize’s machine learning technology intelligently automates data-driven testing in a scalable way. We offer several features that make localization testing a smoother experience.


One of the main reasons that many teams still run manual tests for localization is due to difficulties with scripting automation. Functionize makes it easy to create automated tests with its Chrome extension Architect. The extension is a test creation utility that allows you to capture the flow of your test. You can add visual verifications, enter randomized data into forms, and incorporate test data management (TDM).

Once created, your Functionize tests can detect trends in input data and anomalies in test results. This self-healing capability finds errors in tests and reduces the amount of human effort needed to fix issues related cultural nuances.

Test Data Management (TDM)

Functionize offers enterprise-class TDM with support for many data sources, including an Excel import for TDM. This capability allows users to upload and map data inputs to parameterize tests. Then, you can use Architect to automate localized tests.

For example, you can create a single base test case, let’s say - to test the site in English language. Then, you can orchestrate the test to check different inputs for different runs. In an eCommerce site you may have a “Buy Now” button in English. For the Spanish version of the test, the button should say “Compra Ahora.” You can specify which datasets should be tested in an orchestration. 

This TDM - Orchestration feature allows you to organize and manage your tests. It allows you to do so while ensuring enough coverage for your localized scenarios. You can input data from a spreadsheet or map the data from a database. Functionize is designed to handle a large volume of data variations. 

Functionize Test Cloud

With the Functionize Test Cloud, you can run tens of thousands of tests in parallel and cut the time spent waiting for test results. You can simulate different environments to reflect the infrastructure complexity of your application. You can specify the data center region to simulate the experience for your real end-users. For example, you can run parallel tests from various datacenters around the US and also the APAC region. Then, test for response times, page loads and renders according to localized scenarios.

To find out more about how Functionize can help you leverage AI and ML to strengthen your localization, book a demo now.