Localization Testing: How to QA Localized Sites and Apps

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 involves adapting various elements of a site or software product’s user experience for a specific region or culture:

  • Language, encompassing translation into different languages and dialects (e.g., Australian vs. Canadian English)
  • User interfaces (UI), for example, to accommodate right-to-left languages like Arabic
  • Word choice and tone since some expressions may not be culturally appropriate or don’t have a direct translation in different languages
  • Currencies and payment methods
  • Number, measurement, date, and time formats

That said, localization testing is meant to verify that each of the above elements is fully localized for your target region or culture. It’s a necessary quality assurance step in your workflow.

4 types of localization testing you should do

There are four types of localization testing, each of which assesses something different.

  • Regional or cultural adaptation testing: Are the imagery, currencies, payment methods, and such a fit for the locale?
  • Linguistic testing: Is the translated text clear and accurate?
  • UI or visual layout testing: Are all elements users will see and interact with attractive and easy to understand?
  • Functionality testing: Does your website or app work across different browsers and devices?

Before launching a website or software application, you’ll need to conduct all four tests to confirm that nothing unclear, non-functional, or insensitive goes live. Doing so will guarantee that users can seamlessly navigate your localized product experience, and make them more likely to enjoy it.

After launch, you'll also need to do regression testing whenever you make changes to your website or app code. Retesting confirms that updates haven’t broken any existing features.

Should you opt for a manual or automated process?

As for how you can do each of those four types of testing, you have a few options: manual, automated, or crowd-sourced testing. Each has its pros and cons.

Manual localization testing leverages professional in-country language speakers to test localized content the old-fashioned way. Human testers provide nuanced evaluations of translation quality, cultural appropriateness, functionality, and user experience. However, this expert testing is expensive and time-consuming.

Crowd-sourced testing is similar in that the process is human-driven. But it engages non-professionals to test localized content, meaning it’s often cheaper to do but can lead to inconsistent evaluation speed and quality.

Automated localization testing, on the other hand, uses software to algorithmically test for common issues with encoding, grammar, linewidths, truncation, and so on. As you can imagine, it’s exponentially faster than a fully manual process but is not always as good a judge as a trained human eye. Subtle localization issues may be missed.

Often, the best bet is to use a combination of manual and automated testing to strike a balance between thorough quality assurance, speed, and cost.

How to do website localization testing

What’s the general process for conducting localization testing on websites?

1. Create a detailed test plan

Before anything else, scope your localization testing process by creating 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.

Starting with a detailed plan like this 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, so 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

At this stage, start regional, linguistic, and UI or visual layout testing (the first three types we discussed). Ensure the following:

  • There are no translation errors
  • Text and imagery are culturally appropriate
  • Translated text retains the original message and impact
  • Translated text fits neatly into the website layout
  • Your brand personality still comes across (but in a way that makes sense for the new audience)
  • Date, number, measurement, and currency formats have been adapted correctly
  • The UI isn’t 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

What does checking the functionality or usability of a website involve? Things like making sure all buttons and hyperlinks direct users to the right places, and verifying that all 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 in one place. Share them with your translators, developers, and other relevant team members, so they know what issues to address and can do so right away.

How to perform localization testing for apps

The process for localizing apps is similar but more complex with several additional considerations to keep in mind. Mikhailo Esteves, a software engineer at EC-MSP, explained why:

“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

Since there are more loose ends to tie up here than with websites, test cases are especially critical when testing localized versions of apps.

Example test cases to help you write your own

As mentioned, test cases define scenarios that need to be tested but they’re more than basic descriptions. Test cases require several elements:

  • 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.

What are some challenges of localization testing?

What are some potential obstacles you may run into as you implement the processes above? Here are some of the most common ones:

  • Sourcing native speakers (on your own) to give feedback on your localized site or product experience, especially for less common languages
  • Keeping up with local laws and regulations and maintaining compliance within each region you’re active in
  • Testing all features thoroughly in local languages, particularly if your process is mostly manual
  • Maintaining localized content across multiple product versions and updates since more languages means more maintenance effort

Working with a reputable language service provider like Smartling that offers localization testing services can help you bypass many of these. So can following the best practices below.

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

You should, of course, perform localization testing at or near the end of the website or software development process as a final quality assurance measure. But that shouldn’t 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 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. And don’t forget that you also need to perform testing when making updates to your site or software.

3. Automate where you can

A good localization testing process is both thorough and efficient. Automation can help you strike the right 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 may not be able to provide equally high-value feedback on the technicalities of your website, web application, or mobile app. You need testers with relevant expertise for each type of testing you conduct.

Besides choosing suitable testers, we also recommend sharing additional context beyond test cases:

  • User guides and documentation for your software
  • Visual branding and brand messaging guidelines
  • Translation memories
  • Glossaries with context on industry and brand-specific terminology

These resources will make it easier for testers to identify anything in the localized version of your site or app that doesn’t meet your predetermined standards.

Why do localization testing?

Thoroughly testing a website or software product can be a complex process, but it has its advantages. It helps you understand how your website or app will perform in real-life scenarios, allowing you to identify and fix potentially disastrous issues pre-launch.

To illustrate, 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 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 that bad first impression. You’d likely lose a good percentage of customers for good. (And the negative effects would be even worse if there were a more complex, expensive, or time-consuming issue to fix.)

Localization testing doesn't just protect you from mishaps like this. It protects end users, too, ensuring that they have a positive experience. This can promote ongoing engagement, generate sales, and aid in customer retention.

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 meeting with one of our experts today.