Prepare a Rock Solid Test Environment and Use it
For a Website hosted in English and Japanese Language, it’s not a ball in the browser’s court to change the language of the browser and run the desired test scripts for it. So there comes the need of 2 machines with different language settings in the Desired OS. This is required as users from different countries install OS with their choice of language and generally don’t change their language settings to view a website.
Knowing the Language or having a language translator is a must
If a Speaker of the desired language, belonging to the same region is usually the best person to help in translations, but if it’s not the ball in your court, then use of different translation websites are available like wordreference.com, googletranslate.com, dictionary.com. It is always a good habit to compare results from different translation websites.
Get Maximum Knowledge of the Website
If the functionality for the website with all the business rules for the application is dead clear to you then changing language and checking for functionality for the website with other languages will be a low level headache and will explore the doors as how to test in other language versions.
Check the labels for fields
Check for all the labels present in the website for the language you understand perfectly as it’s the only easiest way to keep track of the dynamic pages in a website in other languages.