What Is Localization Testing and How to Automate It


Anthony Enticknap

14 Dec 2023

9 min. read


When launching an app or website in different countries or regions, test it to make sure it works as expected.

What is localization testing?

Localization testing is a process that allows you to see how your software works in a specific region, before actually launching it.

Pro tip: To make sure your app or website is ready for foreign markets, use the advanced localization testing features of Centus. Learn more.

What is localization testing?

what is localization testing? Localization testing is the process of ensuring software works as intended in specific countries or regions. The testing can involve human testers, automated software, or both. For any business with countrywide or international aspirations, localization testing should be considered essential. Three key points to remember:

Language and cultural adaptation

Localization testing ensures accurate translation, cultural sensitivity, and adherence to language norms.

Functional and technical validation

You can use localization testing to verify that features, formats, and technical aspects all work as expected in the target locale.

User experience and localization quality

By testing your localization, you can build seamless and high-quality user experiences, which will support your expansion efforts.

Two types of localization testing

There are two main types of testing — localization of websites and apps. In both cases, the aim is to make sure your software functions properly in a particular locale. That could be a different country or even a different region, such as a state or province. testing plan development Source: Pixabay

The obvious thing that varies between regions is language, but localization tests cover more than linguistic differences. It’s also crucial to test navigation, user interface design, and compatibility with different operating systems.

How does localization testing work?

Localization testing focuses on verifying the behavior and accuracy of software and content in particular regions or cultures. Due to the complex nature of localization, you may need to use human testers or automation tools. Humans have the advantage of understanding nuance and cultural differences better, while software tools bring the speed and power of automation.

You can also combine human testing and machine testing to reap the benefits of both. Whatever approach you choose, make sure to:

  • validate bugs and defects
  • track test results
  • adjust and refine test cases

Keep reading to learn how to perform localization testing.

Key areas of localization testing

You can test many facets of your app or website, but here are the key areas to focus on.

Language and dialect

If you recreate your content in multiple languages, ensure its readability and suitability for the target audience. Using human testers and translators alongside software solutions, you can check your translated content for grammar, spelling, and punctuation errors. flags Source: Unsplash

Cultural differences

This type of testing checks that your software suits the cultural preferences and expectations of your target audience. For example, you can check to make sure your content uses the right date format and currency for the target region.


Verify that the user interface and basic functionality of your product correspond to the expectations of your target users. If you don’t get this right, you could lose customers or get bad reviews. Usability can be affected by various factors, including cultural and language differences.


Your localization efforts should include compatibility testing. In addition to testing with different operating systems, you need to ensure hardware compatibility. To this end, run a wide variety of test cases to verify that your app or website is ready for global markets. software localization testing Source: Pexels

What are the benefits of localization testing?

If you decide to perform localization testing, your business can benefit in a multitude of ways. Here are a few of the key advantages of the testing process.

Spot issues before they grow

When would you rather discover functionality issues, typographical errors, and other problems — before or after you’ve launched your shiny new app or website?

While you can retroactively fix issues, it’s better if you can nip them in the bud at an early stage. If early testing is performed, you can prevent embarrassing mistakes or stop small problems from growing into something much worse.

Reach more markets

Looking to take your business global? With localization testing, you can step into new markets with your best foot forward. By getting your content right earlier, you can spend less time troubleshooting and more time working on your expansion plans.

You can also take what you’ve learned about localization testing and apply that to future projects. Ultimately, that may mean you can expand faster and further. a globe in a hand Source: Unsplash

Improve your chance of expansion success

If you’re planning to follow in the footsteps of global brands, testing should be a central part of your localization strategy. The localization testing process can help you get your product into the right state for a global audience, highlighting problems so you can create the best possible experience for your target market.

Your preparation could pay off before you know it, giving you a vital edge over your competitors.

Test case example for localization testing

There are many different test cases that you may wish to deploy when getting your software ready for the global market. Typical test cases might include:

  1. User interface testing: Verify translation and display of user interface elements.
  2. Functional testing: Test functionality in the target language and locale.
  3. Linguistic testing: Verify the accuracy and cultural appropriateness of translated content.
  4. Date and time testing: Check formatting and handling of dates, times, and calendars.
  5. Input and output testing: Make sure that when international users type something into your app or site, they see the output they’re expecting.
  6. Currency and numerical testing: Test handling of currency symbols, decimal separators, and numerical formats.
  7. Error handling: Validate error messages and warnings in the localized software or website.

A Test Case Example for Localization Testing

Best practices for localization testing

To get your testing process right, there are a few best practices you can follow to ensure success. From setting up your test environment to getting your localized product out of the door, these measures will help you reach your goals.

Don’t rush it

As with many things in life, it’s better to take your time with localization testing to get it right. You need time to put together a testing team, prepare the software and hardware resources, and build a strategy that’s flexible enough to adapt to unexpected changes. a wristwatch Source: Pexels

You also need to understand your target region and users. Software testing solutions can help, but you’re likely to need human testers as well, to ensure your content is suitable for a particular locale.

Leverage data analytics

Knowing how to gather and analyze data can make a massive difference to localization efforts. If used properly, data can tell you exactly what’s happening and where, but you need to know what you’re measuring and what the numbers mean. data analytics Source:Pixabay

You can use data at every stage of the localization process. For example, understanding your target audience from the start can guide your future localization plans. And when your strategy is in motion, dip back into the figures to see how users are responding to your localized content. Are they using your app or site how you expect?

Use real devices and browsers

While you can do a lot of tests using emulated devices, your development process should also involve real devices and web browsers. As useful as virtual devices are, they’re not perfect. Your software might run well on a simulated iPhone but crash or behave in other unexpected ways on the real one. testing on real devices Source: Pexels

Obviously, you can’t try your content with every combination of software and hardware possible. Instead, test with the devices that are most popular with your target markets.

Test from the start

Anyone who’s ever worked in software product development knows the phrase “Test early, test often.” It's a well-worn and familiar phrase in software testing and for good reason — it can save you a lot of time and pain further down the line.

You should test early because the sooner you spot problems, the quicker you can fix them. It also prevents you from building on faulty work, which could be difficult to undo later.

As for testing often, it’s important because issues can creep into your work at any time. The more frequently you run tests, the simpler it will be to keep everything on track and create an amazing localized product.

Can you automate localization testing?

Yes, there are a variety of automation tools for localization testing that let you automate the key elements of the process. For instance, they can check whether elements in your design are overlapping or hidden, if fonts are displayed properly, or if there are spelling errors in your copy.

Human testing is still important, but AI translation and localization solutions may further bridge the gap in the future.

How to perform localization testing in 6 steps

There isn’t just one way to approach localization testing. You should find a strategy that suits your business and your projects. To get you started, here’s a set of basic steps to consider.

Step 1: Examine the current state of your app or site

Before you even start creating localized versions of your content, it’s essential to know what you already have. Take note of everything that might be affected in different regional settings. This will help when choosing what to test later.

Step 2: Develop a plan

plan development Source: Unsplash

Based on everything you know about your current content, your target market, and the elements you need to localize, draw up a plan. Think about things like:

  • What software tools and hardware you’ll need
  • What you’re changing
  • What you’re testing
  • How you’ll gather and analyze data
  • What you’ll do if your situation changes

Step 3: Set up the testing environment

Next, you need to actually get everything ready for you to start testing. As well as installing the right software, you’ll have to set up rules for automation. If you’re using real devices in your process, you should also make sure they’re ready to go.

Step 4: Set up automation

Wherever possible, it’s a good idea to introduce automation to your localization testing. For example, if you use the quality assurance features in Centus, you can automatically fix a lot of potential issues, including spelling and grammatical errors, inconsistent brackets, and so on.

Step 5: Perform the tests

Perform app or website testing, emulating their functional scenarios. Validate the usability of your product with real users. If necessary, subject the product to performance and stress testing.

Step 6: Repeat the tests

Testing should be a key part of your localization right from the start. You also need to test throughout the process, making sure your software product is ready for new markets.

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