4 Best Practices for Localization Testing

Learn why website and app localization testing is so crucial. Plus, get step-by-step walkthroughs of the process and expert insights on best practices.


Localization testing is a form of software testing. The goal is to verify that a site or software product is tailored for a specific region or culture. The process of localization involves customizing various elements of the user experience:

  • Language, which encompasses translation into different languages, including variants of the same language (e.g. Australian vs. Canadian English)
  • The user interface (UI), which would require adjustments if you were translating into a right-to-left language such as Arabic
  • Word choice and tone since some expressions may not be appropriate or have a direct translation in different languages
  • Currencies and payment methods
  • Number, measurement, date, and time formats

Thus, localization testing checks all of the above.

The four types of localization testing

There are four types of localization testing:

  1. Regional or cultural adaptation testing checks that imagery, date formats, and more are fit for the locale.
  2. Linguistic testing evaluates the quality of the translated text.
  3. UI or visual layout testing ensures all elements that target users will see and interact with are attractive and easy to understand.
  4. Functionality testing verifies your website or app works across different browsers and devices.

Before launching a website or software application, you’ll need to conduct all four. This will confirm that nothing unclear, non-functional, or insensitive goes live. Further, it’ll guarantee users can seamlessly navigate your localized product experience.

(Additionally, even after launch, you'll need to do regression testing whenever you make changes to your website or app code. Such retesting confirms that the updates haven’t broken any existing features.)

How to do website localization testing

How do you conduct testing for websites? The process generally looks like this:

1. Create a detailed test plan

Before anything else, get clear on the scope of your localization testing process. Create a test plan that includes the following:

  1. Test objectives: Outline the goals of the test, such as verifying translation accuracy or cultural appropriateness.
  2. Test environment: Describe the specific language and location settings, device type, and other elements necessary for the test.
  3. Test cases: Outline what scenarios to test, such as the account creation process.
  4. Expected results: State the results expected for each test case.
  5. Resources needed: List any resources needed to complete the tests, such as access to translation services or localization software. Also, list whether you’ll need physical devices. Completing testing on an actual smartphone, tablet, or computer versus using an emulator can give you a more accurate understanding of the user experience.

Why start with a detailed plan like this? It prevents issues from going unnoticed, sparing you trouble—and perhaps embarrassment—post-launch.

2. Mimic the user experience

Whether using an emulator or a physical device, set up the test environment(s) you outlined in your test plan. The goal is to mirror the exact experience a website visitor would have. Therefore, your tester will need to view your site under the following circumstances:

  • In their native language
  • As if you were in their location (via the IP address)
  • On their device type
  • On the operating system they use
  • On their browser of choice

Once that’s done, you begin testing using the localization tools of your choice.

3. Start with high-level testing

Remember the four types of testing we mentioned earlier? At this stage, do the first three: regional, linguistic, and UI or visual layout testing. You might look into the following:

  • Check for translation errors.
  • See whether translated text fits neatly into the website layout.
  • Confirm that the text's message is just as hard-hitting as it is in the source language.
  • Make sure your brand personality still comes across but in a way that makes sense for this different audience.
  • Confirm that date, number, and currency formats have been adapted correctly.
  • Double-check that the text and imagery are culturally appropriate.
  • Note any aspects of the UI that are confusing or unnecessarily complex.

Testers can then move on to making sure the localized version of the site works as intended.

4. Move on to functionality testing

Checking the functionality or usability of a website involves several items such as the following:

  • Making sure all buttons work
  • Vefiying that hyperlinks work and direct site visitors to the right places
  • Checking whether pages load properly and in all the languages you support

In other words, testers should be looking for anything out of order along the user’s journey (or checkout process) on a website.

5. Compile the findings

Compile all observations from the testing into one place. Share them with your translators, developers, and other relevant team members. That way, they know what issues to address and can do so ASAP.

How to perform localization testing for apps

When localizing apps, on the other hand, the process is similar but more complex. There are several extra considerations to keep in mind. Mikhailo Esteves, a software engineer at EC-MSP, says:

“Apps often have more interactive elements than websites, such as buttons and menus. These need to be tested to ensure they are properly translated and function correctly. Additionally, apps may also have different text input methods, such as keyboard layouts, which need to be considered during testing.”

And that’s not to mention that testing needs to account for the following:

  • Different screen sizes
  • Different operating systems
  • Device-specific features
  • Hotkey functionality across devices
  • Prevention of text truncation or broken layouts if a target language takes more space than the source language
  • Correct font loading for different languages

As you can see, there are more loose ends to tie up with apps. So, while you should create test cases for websites too, they’re especially critical when testing localized versions of apps.

Example test cases to help you write your own

As mentioned, test cases define the scenarios that need to be tested. But writing test cases requires more than just general descriptions of each scenario. It requires, among other things, these items:

  • Test case IDs so there’s no confusion about what test results apply to which test case
  • “Repro steps” or instructions on how to reproduce each scenario
  • Intended results so testers know what to expect and can correctly identify issues

Plus, there should be space for testers to record the actual result after running each test case, and to comment on any observations.

Need a better idea of what test cases look like? Here are some examples of what you might see on an actual localization testing project.

Test Case IDDescriptionRepro StepsIntended Results
Case_01Confirm correct currency is displayed for target region.Visit the pricing page.All pricing should be displayed in Euros.
Case_02Verify that all links are functional.Click the “Schedule a Demo” and “Get Started” buttons on the pricing page.“Schedule a Demo” should link to the contact page. “Get Started” should link to the account creation page.
Case_03Verify that validation messages appear for input fieldsVisit the “Schedule a Demo” page and fill out the contact form.Contact form will be submitted successfully if inputs meet the requirements.
Case_04Verify that password creation rules are working.On the “Create Account” page, enter an email address and a password of at least nine characters.Account will be created if password meets the minimum requirements. Error message will appear if password does not adhere to requirements.

4 best practices for localization testing

Regardless of the scenarios you need to test, there are some best practices worth sticking to.

1. Start with research

For the most efficient localization process possible, do your due diligence. Get familiar with the target market you’ll be localizing your products for. Learn the cultural nuances and preferences of your target audience. And, as much as possible, work with professionals (qualified translators) who have deep knowledge in those areas.

2. Test as you go

When should you perform localization testing? Definitely at or near the end of the website or software development process. It's a smart final quality assurance measure. But that should not be the first and only time you test. Imagine spending dozens of hours on localization only to find several significant UI issues. It would be a headache—not to mention a poor use of your time—to have to backtrack and fix those problems. It’s much more efficient to test at several points during the process (on various devices and browsers) and fix issues as they arise.

3. Automate where you can

Your localization testing process should obviously be thorough. But it should also be efficient. Automation can help you strike that balance. Deeply familiar with localization processes, Lucjan Suski, Co-Founder and CEO of Surfer, advises the following:

“Use automation tools such as Selenium WebDriver where possible. This will allow you to quickly run through scenarios multiple times with varying input data before having humans test them manually afterward if needed. This way, you get maximum coverage while still ensuring quality output. After all, manual testers can spot issues quicker than machines sometimes due to their familiarity with native languages, for example.”

Yet, this raises an important point. For best results, you don’t just need to include human testers in your process. You need to have the right kind of testers involved at the right time. Let’s get into that next.

4. Choose localization testers wisely (and set them up for success)

To illustrate our last point, you’ll want native speakers and local experts to provide feedback on translation quality. However, they likely won’t be best suited to give feedback on the technicalities of your website, web application, or mobile app. This highlights the value of having testers with relevant expertise for each type of testing you conduct.

But aside from choosing suitable testers, it’s also essential to provide sufficient context. Beyond sharing test cases, you may want to offer other resources:

  • User guides and documentation for your software
  • Brand guidelines (encompassing both visual and messaging-related aspects of your brand)
  • Glossaries complete with context on industry and brand-specific terminology
  • Translation memories to ensure consistent, high-quality translations

Why do localization testing?

Thoroughly testing a website or software product can be a complex process. But just as localization has benefits, localization testing also has advantages. It helps you understand how your website or app will perform in real-life scenarios. This is especially valuable because it lets you find and fix potentially disastrous issues pre-launch.

Imagine launching a localized version of your e-commerce store. You’ve hyped it up for months through your marketing channels. Potential customers are ready to buy.

Yet, on launch day, support messages start pouring in, saying that your checkout flow is broken. People are panicking about being charged but not getting order confirmations via the website or email.

You could fix this issue fast—say, within a few hours. But it’ll be tough to make up for a discouraging first impression, even if some people are open to buying from you again in the future. Plus, you’ll likely have lost a percentage of customers for good. (And think of how much worse it would be if there were a more complex or expensive issue.)

Localization testing doesn't only protect you from mishaps like this. It protects end users as well, ensuring that they have a positive experience. This can promote ongoing engagement and eventual conversion.

Take the reins on localization and localization testing

Ultimately, being smart about how you approach localization can make testing faster and easier. For instance, a top-tier translation management system can save you time and money, all while helping you maintain high quality standards.

Smartling customers, in particular, request 48% fewer changes, meaning fewer issues to resolve after testing. Overall, this contributes to a 42% faster time to market.

For more on how Smartling can simplify the process of localizing your website or software product, schedule a chat with one of our experts today.