Guidelines and Considerations for Setting the 'Primary Language' in Shopify Cross-Border E-Commerce Construction

Mar 11, 2026

table of contents

1. Introduction 2. Three impacts of "first language" on a website 3. Japanese vs. English: Which should be your first language? 4. [Technical Considerations] The "Language Barrier" that arises when customizing notification emails 5. Summary

1.First of all

When building a cross-border e-commerce site with Shopify, the initial setup is one of the challenges you will face."What will your first language (primary language) be?"That's the option.

If you simply decide to "create it in Japanese first and add English later," you may encounter unexpected limitations in later SEO strategies, notification email customization, and app integration.

This article will organize the criteria for making such decisions from a director's perspective.

2. Three impacts of "first language" on a website

In Shopify, the primary language is not simply the "main display language," but a setting that is fundamental to the system.

　1. Determining the URL structure

The first language is the root domain (example.com/) is assigned, and additional languages are in subdirectories (example.com/en/(and so on.)

　2. Base language of notification emails

Automated emails such as order confirmation and shipment confirmation are based on templates in the primary language.

　3. External integration and application behavior

Some overseas apps and social media integrations may be designed with the assumption that the user's primary language is English.

3. Japanese vs. English: Which should be your first language?

The criteria used during the initial consultation for system development are summarized in the following comparison table.

project	First language: Japanese	First Language: English
Main target	Mainly domestic users	Mainly overseas users
SEO Priorities	Prioritizing search traffic within Japan	global(https://www.google.com/search?q=Google.com等)
Application and Management	I am familiar with Japanese administration screens and input methods.	I have no problem managing data in English.
URL construction	example.com/ (Japanese)	example.com/ (English)

4. [Technical Considerations] The "Language Barrier" that arises when customizing notification emails

Changing the primary language after a website has been built carries significant risks, including the impact on SEO due to URL changes and inconsistencies in translation data.

In particular, the amount of work tends to increaseCustomizing notification emails (such as order confirmation emails)is.

Liquid code is based on the first language
Shopify notification email templates are considered "correct" if the code is written in the user's primary language.
Logic such as changing wording under specific conditions (ifWhen typesetting text (such as sentences), if the base is Japanese, there are cases where the preview is distorted or the translation is not reflected when it is expanded to other languages.
The limitations of translation apps
Translate & Adapt While apps like these can translate notification emails, there are instances where certain buttons or dynamic variables within the email (such as the estimated delivery date) may not be fully translated due to being affected by the primary language setting.
Increase in verification workload
If your first language is Japanese, test emails will generally be sent in Japanese.
To verify that emails in other languages are displayed correctly, it is necessary to actually create test orders, switch the customer's language settings, and repeatedly perform sending tests, which significantly increases the verification time.

Before deciding to start with Japanese,"How much detail should we put into creating the notification emails?"It is necessary to carefully consider the operational level and then decide on the first language.

5. Summary

"What to choose as the first language" is something that e-commerce sites decide."Who should be our top priority customer?"That's the very essence of their business strategy.

To avoid situations where, after development has begun, the client later decides they actually wanted to focus on English, it is the director's crucial role to thoroughly discuss future overseas sales ratios and SEO prospects with the client during the requirements definition phase.

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